Category Archives: Places

Prehistoric Trackways National Monument

Tiny tracks from 280 million years ago are preserved in red siltstone.

Tracks in the Rocks

Mountains are nature’s mystery novel. Captured in layers of rock are stories about time, about life, about death. As I pass the Robledo Mountains just northwest of Las Cruces, New Mexico, I ignore the dry, sparsely vegetated cover, knowing an extraordinary story awaits me within the rock of the Prehistoric Trackways National Monument.

The monument, managed by the Bureau of Land Management, is relatively new, so infrastructure consists of a few interpretive panels, two dirt parking lots, and a hiking trail that switches up the hillside. I called ahead and signed up for a guided tour—the best way to discover the secrets of the Robledos.

Colin Dunn, paleontologist with the Bureau of Land Management, shows us a rock loaded with fossils.Skip the Dinosaurs

On that bright, spring, Saturday morning, a small group of hikers gather around Colin Dunn, the BLM paleontologist. We’ve come to see the fossilized trackways of creatures that squelched through mud 280 million years ago. “We’re skipping the dinosaurs,” Colin says. “Mammals, flowers, birds. Just skip it.” These tracks were made by animals 60 million years before any flower bloomed or dinosaur roamed the earth.

The trackway eroding from the Robledo Mountains dates to the Early Permian. At that time, New Mexico was part of a single, massive continent known as Pangea. The rocks that surround us are sediments from a shallow, warm sea that lapped against a tropical shoreline.

Fragments of sea urchin spines and shells make a jumble of shell hash in a rock.Shell Hash

We hike up a dry creek bed. Colin stops to show us long, thin sea urchin spines, round disks of crinoids (sea lilies), flat colonies of bryozoan, and ridged shells of clam-like brachiopods. These fossils create a layer of “shell hash”—a jumbled assortment of life in the Permian sea.

Tracks of a Dimetrodon are deeply impressed into red siltstone.


As we move inland from sea to shoreline, thick beds of red rock jut from the hillside. Colin scrambles to the first terrace. Crouched before a large, flat slab of siltstone he points out a series of tracks. About the size of my hand, the “palm” of each print is round and deeply impressed. The toes are long, thin, and sharply pointed.

“These are Dimetrodon tracks,” Colin tells us. Dimetrodon was the terrestrial terror of the Permian world. Lizard-like, with a bony sail fin down its back, the largest Dimetrodon was 13 ft. long and weighed 500 lbs. “This one was pretty small,” says Colin. “It was only about 100 lbs.”

Colin pulls a small rock out of his pocket. Clusters of three lines, each arranged like an arrow, cover the surface. “I was at White Sands and saw beetles making tracks just like this. I was totally geeking out!”

Walchia fronds from an upland forest washed downstream and pressed into the mud.Walchia Fronds

I am too. Fossilized bones fascinate me, but these tracks? Even better. Bones write the story of death. These footprints tell the story of life. I can picture an araeoscelid (go ahead and think lizard) scampering for cover, a beetle making its way across the mud, and the corkscrew twist of a worm as it drills a burrow. Raindrops dimple one rock; a mat of Walchia tree fronds from an inland forest is impressed on another. The fronds look like the potted Norfolk Pines I used to buy at the home improvement store.

By studying these tracks, paleontologists are unveiling twists to the mystery of Permian life. Initially, scientists believed Dimetrodon was a low-slung, lumbering thug. But the tracks—set close together and lacking belly scrapes or tail drag marks—suggest Dimetrodon was a sprinter rather than a plodder.

Colin tells me of petrified log jams and other track sites at the monument. He won’t share where they are though. “Have you heard of Fossil Cycad National Monument?” he asks. I shake my head, no.

“That’s the problem. Fossil Cycad had one of the world’s greatest concentrations of cycads. Then people came in and took them all. They shut down the monument because there wasn’t anything left to see. I don’t want that to happen here.”

I don’t either.

A sign at the monument tells of the trackway discovery and warns people not to collect rocks.

Getting There:

The Prehistoric Trackways National Monument is open to the public, but the best way to visit is with a knowledgeable guide. Tours to the Discovery Site are given once a month on Saturdays. Contact the Bureau of Land Management for more information.

To Learn More

Traces of a Permian Seacoast is a wonderful, beautifully illustrated book about the fossil trackways of Prehistoric Trackways National Monument. Purchase it from the link below to help support this blog!


Also posted in Chihuahuan Desert, Fossils, Geology, New Mexico, Travel

Ghosts of the Past: Stromatolites

The 1.25 billion year old Castner Formation is exposed in the Franklin Mountains near El Paso.

I believe in ghosts. They hide in plain sight, urging us to listen to the stories they have to tell.

It was my birthday and, feeling just a wee bit sorry for myself (I’m of that age), I decided to go in search of something older than I was—the stromatolites of the Castner Marble in the Franklin Mountains near El Paso. Now, these stromatolites aren’t just a little older than I am, they’re way older than I am. About 1.25 billion years older. Yes, that’s right: 1.25 billion.

Math isn’t the strongest of my academic skills, but let’s work our way through this. Let’s say you wanted to count to 1.25 billion—just to get a sense of how colossal that number is. If you keep up a steady rhythm of a number per second (and absolutely no stopping for dinner, a potty break, or Facebook), it will take you 40 years to reach 1.25 billion. If you wanted to restrict your counting to a mere 8 hour day, buckle down for 120 years. Hopefully, you don’t get confused, skip a number, and have to start all over. That would be depressing.

Tiny, single-celled cyanobacteria create layered sedimentary rocks.

So I’m in search of 1.25 billion-year-old stromatolites. In case you’re wondering, stromatolites are a type of sedimentary rock created by single-celled photosynthetic cyanobacteria (that’s blue-green algae). These microorganisms like to congregate in large groups, forming sticky mats in shallow water along a shoreline. I don’t think anyone knows why the stickiness is necessary, but the result is that the bacterial mats accumulate sediment that clogs the system up. The bacteria, being photosynthetic, need the sun’s energy to produce food, so they move upwards, forming another mat on top of the sediment. And so it goes. Layer after layer, eventually forming a cauliflower-shaped lump of rock in shallow water.

Now the amazing thing is that these single-celled cyanobacteria have been carrying on like this for over 3.2 billion years. In fact, stromatolites are some of the oldest fossils in the world. They reached their peak diversity just about the time the Castner Marble stromatolites formed. After that, they’re harder to find. The theory is that grazers evolved that found a stromatolite mat downright tasty and pretty much ate them to near-extinction.

Arizona Barrel Cactus (Ferrocactus wislizeni) have hook-shaped spines that can grab an unsuspecting ankle.

I cajole a geologist friend into going with me, and we head westward, driving past yucca-studded grasslands and mesquite-topped sand dunes. We skirt El Paso and climb the Trans-Mountain Highway through the Franklin Mountains. I navigate, reading directions from the Geological Excursions to a Transmountain Precambrian Adventure field guide that I’d downloaded from the internet. We’re looking for Stop 2—the Castner Marble Stromatolites. A gust of wind shakes our vehicle as we round the corner.

We pull over onto a wide gravel patch (obviously not the first geologists to investigate this location) and begin walking back down the highway to the end of the guardrail. Another gust of wind nearly knocks me off the mountain.

The authors of the field guide suggest that we follow a small trail down into the valley, and up the other side. The stromatolites will be there.

The trail is, indeed, narrow, and very steep. I cautiously make my way down, trying to avoid the baseball-sized round rocks that ensure a quick—and most likely painful—descent down the slope. I skirt the lechuguilla, prickly pear cactus, and a barrel cactus or two to arrive at a 2 to 3 ft thick band of light-colored rock.

A layered band of stromatolites are exposed in the hillside.

“Are you sure these are stromatolites?” I ask Blaine. He’d gotten there before I had and was poking and prodding at the rock as geologists tend to do.

“Yeah, sure. Look.” He points to the thin, wavy layers in the rock. And there, right before me is evidence of the earliest life in the Chihuahuan Desert.

With just my naked eye I can distinguish layer after layer of sediments trapped by cyanobacteria over a billion years ago. To see the actual fossils, I’d need something slightly stronger, like a microscope. Most of the layers are flat-lying to slightly wavy—an indication that the mats collected sediments in relatively calm waters.

Stromatolites aren’t flashy like a trilobite fossil or spectacular like an ammonite. But all in all, they’re probably far more important. Stromatolites hint at the origin of life. When the cyanobacteria were trapping these sediments, the skies were pink—filled with methane and ammonia and other gasses that would kill us today. The land was barren. Not a single, living thing existed out of the water. But in the water, slimy mats of green bacteria clung together, creating their own little rock. The cyanobacteria were photosynthetic, and that nifty trick of converting the sun’s energy and some carbon dioxide into food while releasing oxygen as a byproduct was changing the world. A few billion years of lilliputian, single-celled bacteria releasing minute bubbles of oxygen created an oxygen-rich atmosphere necessary for complex life to evolve. Take a deep breath. That’s you I’m talking about.

Living stromatolites are pretty rare now, but they’re still around. In Cuatro Ciénegas, a desert wetland in the Chihuahuan Desert of northeastern Mexico, stromatolites can be found in the pozas or spring-fed pools of the marsh.

Scientists working at Cuatro Ciénegas cored one of the active stromatolites. The mat consisted of a complex community of microorganisms—not just cyanobacteria. The top layer was composed of diatoms (distinctive algae with transparent cell walls), below that was photosynthetic cyanobacteria. A third layer consisted of purple sulfur bacteria. These bacteria photosynthesize using hydrogen sulfide rather than water and produce elemental sulfur as their byproduct. Below that was a sulfur-reducing bacteria that takes the elemental sulfur and reduces it to hydrogen sulfide. “Each layer obtains and processes energy in a different way and produces different waste products, and yet it is an interactive community where each layer contributes to the survival of the mat as a whole,” the scientists concluded. Stromatolites are all about being good neighbors.

Stromatolite band exposed in the Franklin Mountains near El Paso.

I poke around the rocks, distracted by rainbow cactus with fat buds, and a lizard warming itself in the sun. None of this would be possible without those little cyanobacteria that lived in an ancient sea long, long ago. I wave at Blaine, who’s wandered off to look at a contact or something geological and we head back to the car. Finding rocks that are billions of years older than I am, makes me happy—all in all, a pretty spectacular birthday.

Also posted in Chihuahuan Desert, Fossils, Geology, Texas

Places: West Texas Rest Stops

"Watch for Snakes" Warning Sign at a rest stop in west Texas

Watch for Snakes!

I’ve always thought of roadside rest stops as a necessity. You’re in, you’re out, you’re on your way. But I’m working on a photography project about the history of automobile tourism in West Texas, and I’ve started looking at rest stops in a slightly different way.

I grabbed my camera at this rest stop on I-10 between Balmorhea and Fort Stockton when I saw the “WATCH FOR SNAKES” sign. I’ve noticed warnings like this before, but they’re usually on a path leading to the picnic tables. This prominent sign made me think. Should I watch for snakes in the restroom? Given the fact that the rest stop is in the Chihuahuan Desert of West Texas, and that the restrooms have cool, tile floors, it wouldn’t surprise me at all if I found a rattlesnake curled up next to the toilet.

So I was on the lookout for snakes.


Buffalo Soldier with his horse

Buffalo Soldier Tile Mural

But I found something even more wonderful. Across the bathroom wall was this tile mural of a 19th century Buffalo Soldier and his horse. The Buffalo Soldiers were African-American infantry and cavalry troops stationed at Fort Stockton (1867-1886) and Fort Davis (1867-1885) after the Civil War. The soldiers were responsible for protecting travelers on the San Antonio-El Paso road, constructing telegraph lines, guarding watering holes, and conducting campaigns against raiding Apache and Comanche warriors.

This mural made me think. Were all of these mid-1960s rest stops decorated with murals depicting local history? I grabbed my map, checked for the next rest stop, and headed east.


A theropod dinosaur stomps across the landscape

Acrocanthosaurus Stomps Across a Cretaceous Swamp in Pecos County

The next stop was just past SH 190 (the Iraan turnoff).

Here, a salmon-pink dinosaur stomps across the wall, glittering white teeth bared. This one puzzled me at first. A dinosaur? Out here? But then I remembered a roadside park near Girvin (a few miles northwest of the rest stop) where, 120 million years ago, a theropod dinosaur squelched through the mud.  In 1965, highway workers uncovered its three-toed tracks preserved in the limestone of a creek-bed. Paleontologists decided that an Acrocanthosaurus—a genus of dinosaurs that existed in the early Cretaceous (125 mya to 110 mya) and had a distinctive short ridge along its spine—left the tracks as it foraged along the shore of an ancient sea.

Eureka! I was on to something. Like a bloodhound hot on the trail, I started looking for rest stops. The 1960s-era rest stops were not only examples of quirky, fun public art, but also related to the history of the region. I love this kind of thing.

Brands and an oil rig are depicted in the Nolan County rest stop.

Brands and Oil in Nolan County off Interstate 20

Over the next couple of days, I went on a rest-stop treasure hunt. Even my mom got involved. I’d promised her a Grand Adventure for Mother’s Day and suggested we drive the backroads of Central Texas looking at wildflowers. Instead, she remembered an old rest stop up near Fort Worth. Could we go check it out? You’ve just got to adore mothers like that. The old rest stop near Fort Worth was gone, but we discovered some other treasures.

The Nolan County rest stop (on I-20 between Sweetwater and Trent) was the most complex one that I visited on my three-day trip. Tile-work murals cover the entire bathroom. A frieze of historic brands circle the walls and against the back wall is an oil rig, quail, deer, and a variety of other wildlife.


Standoff between a cowboy and his Hereford.

Cowboy and Herefords, Nolan County

On the side wall of the Nolan County rest area the mural continues, depicting a cowboy with his Herefords. As with the other murals, there’s a story to tell. Nolan County was founded in 1876 and by 1880, there were 52 ranches in the area. Herefords, a British breed that was exceptionally suited to the Texas environment, gradually replaced Longhorns as the cattle of choice on the ranches. I wondered if the brands shown on the walls were those of the first 52 ranches, so I gave Melonnie Hicks, the Executive Director of the Pioneer City-County Museum in Sweetwater, a call. I caught her at a bad time, and she wasn’t sure about the brands. But, she told me, the museum has actual brands from those historic ranches, and anyone that’s curious can drop by the museum and take a look.

The oil rig is a nod to the discovery of oil in Nolan County in 1939 and an oil and gas industry that boomed in the 1950s.


Exhibits in rest stop on Interstate 20

The History of Auto Tourism Exhibit in Eastland County

I have to admit that I have a fondness for the old-style rest stops and their art, but I can see why the Texas Department of Transportation is replacing some of them with new, mega-safety rest areas. The old ones are small. Some are dark. People complain that there aren’t doors on them, making them potentially unsafe.

In 2001, TxDot began building a different style of rest stop. These are big, open, airy buildings with lots of parking, playgrounds, and even WIFI. But they’re more than that. To reduce the number of fatigue-caused accidents, TXDot engineers wanted people to stay longer. They worked with county historical commissions, schools, and other local groups to create rest areas that portrayed the local community. In a sense, they’re small museums, complete with interpretive panels, artifacts, and hands-on, computer-based interactive exhibits. They’re a destination on their own.

So next time you’re out for a long drive, pull off and enjoy the art and history of Texas rest stops. Which are your favorites?

Also posted in Chihuahuan Desert, Texas, Travel Tagged , , , , , , |

Places: Big Bend Ranch State Park’s Arroyo Mexicano

Big Bend Ranch State Park covers 311,000 acres of the Chihuahuan Desert.

Big Bend Ranch State Park: The Other Side of Nowhere

Big Bend Ranch State Park hugs the Mexican border and sprawls over 311,000 acres of the Chihuahuan Desert in West Texas. State park staff affectionately call it “The Other Side of Nowhere.” To the casual visitor, the park appears to be all rugged mountains, deep canyons, and miles and miles of rough roads designed to destroy your vehicle and shake the fillings loose from your teeth.

But those rugged mountains and deep canyons hold treasures if you’re a naturalist. The rough roads? They’re just a necessary evil if you want to experience the park.

Groves of cottonwood and ash trees line the bottom of Charro Canyon.

Cottonwood, Ash, and Oak Trees Line the Bottom of Chorro Canyon

I spend two days with Blaine Hall and Roy Morey exploring sites for a Native Plant Society of Texas field trip. Blaine aka “Big Foot” wears one shoe 3 sizes larger than normal to accommodate the brace and bandages that stabilize an ankle broken during a hike two weeks ago. Recently retired from his position as the interpretive ranger for Big Bend Ranch State Park, Blaine chatters away, teasing Roy and me, and pointing out geologic features as he skillfully guides the truck up rock-covered slopes, across ridges of limestone, and down sandy washes. He pulls over frequently so that we can enjoy the view.

Roy is quiet, not letting Blaine’s teasing phase him. Roy is a plant person. After retirement, he moved to Terlingua and began compiling photographs of the plants of Big Bend National Park. His hobby became a full-time pursuit, ultimately resulting in Little Big Bend: Common, Uncommon, and Rare Plants of Big Bend National Park. Once he completed that book, Roy shifted west and began working on a companion volume that will describe the plants of Big Bend Ranch State Park.

“I need to get up there someday,” says Roy, looking up at the sheer cliffs of a mountain. I’m surprised. Between Roy and Blaine, I would have sworn that they’ve walked every inch of the park’s 311,000 acres.

Today, we’re looking for unusual plants, so we head for Arroyo Mexicano, a box canyon that ends at Mexicano Falls. Canyons often harbor botanical treasures such as groves of cottonwood and ash trees and tiny plants that cling to the rock walls. Canyon walls protect plants from the harsh sun and fierce winds of the desert and often have seeps and springs that provide extra moisture. “One of the only mountain laurels in the park is up Arroyo Mexicano,” says Roy. “I hope it’s still alive.” It was.

An ammonite impression in limestone.

A Dinner-Plate Sized Ammonite Fossil in the Limestone

“Want to see an ammonite?” Blaine asks as we drive down Fresno Canyon. The creek has eroded deeply into the rock, exposing the flat-lying, flaggy Cretaceous limestone of the Boquillas Formation and the nobby, white limestone of the Buda Formation.

We pile out of the truck to admire the dinner plate-sized ammonite lying exposed on an upturned piece of Boquillas limestone. The thick limestones and this ammonite fossil are evidence of a time when a shallow sea covered part of Texas. You won’t see ammonites swimming around today. The last of them went extinct when a giant meteorite struck the earth about 66 million years ago. The short and long-term effects of the meteorite impact—wildfires, tsunamis, and clouds of debris that blackened the skies and blocked the sun for years—killed about ¾ of Earth’s plants and animals.

A Mexican Buckeye Provides Nectar for Pollinators

Mexican Buckeye Tree on the Edge of the Arroyo

We eventually arrive at the mouth of Arroyo Mexicano, shoulder our packs, and trudge our way up the canyon. I’d like to say that we hiked briskly, but I have to admit that I’m a trudger in soft sand. Fairly quickly, we see pools of water and a shallow stream meandering its way across the sand bottom. Groves of cottonwoods, their new leaves a beautiful, fresh spring green, provide shade along the way.

Occasionally a spot of pink reveals the location of a Mexican buckeye tree. These early-blooming shrubby trees are an important source of nectar for bees and butterflies. A Mournful Duskywing flits between flowers, ignored by a nectaring Grey Hairstreak. I search unsuccessfully for a Henry’s Elfin—a small brown and silver butterfly that uses Mexican buckeyes as a host plant. Henry’s Elfins are more common in the eastern United States, so seeing one in West Texas is pretty special. Roy and Blaine have moved on, so I quit looking for butterflies and hurry to catch up.

Huge velvet ash trees with their gnarly roots exposed.

Velvet Ash Trees in the Arroyo

As we move up the canyon, we walk under large velvet ash (Fraxinus velutina) trees. I am fascinated by the texture of the bark and the thick, gnarly roots wrapped around giant boulders. Of course, the exposed roots are also a warning sign. This canyon carries water—often with enough force to roll boulders and wash away enough sediment to expose the roots of trees. I check out the sky (gray clouds gathering) and look for high ground. The vertical walls of the canyon look back. I’m doomed.

Conglomerate boulder made of smaller, rounded, igneous rocks.

Volkswagen-sized Conglomerate Boulder in the Arroyo

In places, we skirt boulders the size of Volkswagon Beetles or larger. I envy Blaine his ability to read these rocks. “See,” he says, “this rock is made up of older rocks that have been cemented together to form a conglomerate.” This particular conglomerate is just a baby rock if you can wrap your mind around geologic time.

All of the “clasts” or smaller rocks that make up the conglomerate are volcanic in origin which means they were deposited about 27 million years ago. Over time, they broke away from their parent rock, were tumbled and smoothed, and came to rest in one place long enough for the white matrix rock to cement them all together again. The conglomerate eventually broke up, and Volkswagon-sized boulders tumbled down the slope, coming to rest in the stream bed.

Fern-covered walls and plunge pool of Mexicano Falls

Mexicano Falls at the End of the Arroyo

After about 3.5 hours of walking and stopping to admire rocks, plants, and scenic views we reach the end of the canyon. At this time of year, Mexicano Falls is more of a drip than a fall. Maidenhair ferns, yellow-flowered columbines, and thick carpets of moss fill the cracks where water seeps from the rocks. The plunge pool is thick with green algae.

Blaine points to a gap in the canyon rim where water funnels through to create a waterfall during the summer rainy season. I’d love to be there to see the waterfall, but then I remember those exposed roots and the flood debris wrapped three to four feet high up the trunks of the trees that we were walking through earlier. Flash floods are real and dangerous in this canyon.

The tiny, yellow, fringed monkeyflower hangs from the wet walls of the canyon.

Fringed Monkeyflower Hangs from the Wet Walls of the Canyon

While Blaine and I photograph the ferns and columbines, Roy walks the face, scouring the seeps for fringed monkeyflower (Mimulus dentilobus). “Found it!” he calls. Fringed monkeyflower is a rare plant in Texas, found only in places where water drips from the West Texas mountains. I’m surprised by how tiny it is. The bright yellow flower with its fringed petals and red spots in its throat rises above a mat of small leaves hugging the wet rock face. We’re lucky to find these in bloom. It’s only March and according to the field guides, fringed monkeyflower blooms from June to August.

Blaine and Roy fix a flat tire.

Flat Tire

The wind begins to blow, and the clouds build, getting thicker and grayer. We decide to return to the truck before a storm drenches us. The hike back takes about 2.5 hours. We quickly pack up and drive off, but Blaine stops almost immediately. He walks around the truck and discovers a flat tire. “That’s two this week,” he mutters. Razor-sharp rocks can slice through the sidewalls of a tire and mesquite thorns pierce treads easily. We unload all the gear to access the spare, and Blaine and Roy begin the laborious task of changing the tire. Fortunately, nothing goes wrong and within 30 minutes we’re back on the road. We eliminate a couple of side trips and head straight back to the park headquarters at Sauceda. Driving any further than necessary without a spare is foolish.

The flatirons of the Solitario provide a perfect backdrop for a patch of Big Bend Bluebonnets.

Big Bend Bluebonnets and the Solitario

Since Blaine and Roy have the flat-tire situation in control (and they’re a bit annoyed with my photographic documentation of the event), I wander off a few feet to photograph a patch of Big Bend bluebonnets with the flatirons of the Solitario in the background. The Solitario is a massive igneous dome created when molten rock pushed up the flat-lying rocks above it creating a circular feature 10 miles in diameter. The dome attracts geologists, botanists, and naturalists from around the world and is probably the most famous feature in Big Bend Ranch State Park.

I love going to the Solitario, but this opportunity to explore Arroyo Mexicano with Blaine and Roy was as close to perfect as a day could be.

Also posted in Chihuahuan Desert, Geology, Plants, Texas Tagged , , , |

Places: Bitter Lake National Wildlife Refuge

Sandhill Cranes and geese head south

Sunrise at Bitter Lake National Wildlife Refuge, Roswell, New Mexico

The alarm goes off at 5 a.m. It’s cold, but I resist the urge to roll over and go back to sleep. I want to photograph Sandhill Cranes today, and they fly at dawn. I load up my camera gear and head for the Bitter Lake National Wildlife Refuge about 10 miles northeast of Roswell, New Mexico.

It’s a chilly 23F as I arrive, but the birds aren’t sleeping in either. As the sky brightens, they stir, murmuring and honking softly to each other. There are hundreds of Sandhill Cranes and thousands of Snow and Ross’s Geese in the shallow ponds of the refuge. Northern Shovelers, elegant Northern Pintails, and Mallard ducks disappear into the reeds as I stop to watch the sun come up.

The Sandhill Cranes and the geese take off, groups of birds bursting into flight all at once. They rise quickly into the air, to form V-shaped skeins as they head south.


Joseph R. Skeen Visitor Center overlooks wetlands

History of the Bitter Lake NWR

The Bitter Lake National Wildlife Refuge consists of 24,609 acres of wetlands along the Pecos River. Sinkholes, playa and oxbow lakes, freshwater springs, marshes, and man-made impoundments create a variety of aquatic habitats. Water in the desert is precious and tends to concentrate a broad range of species. Here, the wetlands support over 350 species of birds, 28 types of fish, and 110 dragonfly and damselfly species.

The refuge was established in 1937, three years after the passing of the Migratory Bird Conservation Act. The Act gave the federal government authority to purchase land for wildlife refuges. Although the refuge system was designed to protect upland game, mammals, and song, insectivorous, and ornamental birds; in the early years, waterfowl was clearly the focus.

By 1937, the region had suffered through 3 years of severe drought. Crops didn’t grow. The soil, no longer held in place by prairie grasses and forbs, blew away in billowing clouds. The once productive farmlands of the plains became known as the Dust Bowl. Waterfowl were hit hard by the drought, although overharvest by unregulated hunting and the draining of the wetlands to create farmland also took their toll. Early conservationists “Ding” Darling, Thomas Beck, and Aldo Leopold declared that waterfowl were in a state of crisis and called for an aggressive plan to create federal wildlife refuges.

Bitter Lake was chosen as one of the first wildlife refuges because of its location along the Central Flyway. The flyway—a great migratory route that cuts a swath across the middle of North America—is home to most of North America’s ducks and geese. Tens of thousands of birds move along the Flyway each year, flying north to breed in the summer and south for the winter.

Today, the refuge is known as much for its incredible diversity of dragonflies and damselflies as it is for its birds. The refuge also protects rare species including tiny snails the size of a glass seed bead, that cling to decaying leaves in the ponds. Shrimp-like amphipods—about the size of a lima bean—scoot across the bottom of sinkholes, and small fish dart for cover when a shadow crosses the pond surface. Many of these creatures can be found nowhere else in the world.


Exhibits explain this unique oasis in the desert.

The Joseph R. Skeen Visitor Center and Refuge Trails

Start your visit at the Joseph R. Skeen Visitor Center. There’s a 15-minute orientation film about the natural history of the refuge, beautiful interpretive exhibits, and even a tank of rare fish.

The back porch overlooks a large pond. With a pair of binoculars, you could sit out there all day and watch the American Coots and ducks going about their business. But to get the most from the refuge, jump back into your car and drive the Auto Tour or go for a hike.

Bitter Lake and the northern part of the refuge are closed to visitors, but the 6.5 mile Auto Tour loops around the ponds at the southern end of the refuge. The well-maintained dirt road is easily accessible by car. Along the loop,  several pull-offs guide you to overlooks where you can set up a scope and get a good look at the bird activity.

If you’d like to hike, five short hiking trails branch off from the Auto Tour road.  The trails lead into the uplands, around an oxbow lake, or out to observation blinds. They range in length from about 2 miles for the Oxbow Loop Trail to a short 0.2-mile butterfly trail.


Hundreds of Sandhill Cranes gather in the shallow ponds for the night.

Sandhill Cranes Gather For the Night

There’s something special at the refuge every season, but I was there in winter and specifically looking for the Sandhill Cranes and waterfowl that overwinter in this part of the Chihuahuan Desert. The Sandhill Cranes and light geese (a mix of Snow and Ross’s geese) leave the refuge at dawn to spend the day in nearby farm fields. At dusk, they return to the refuge to roost for the night in the shallow pond water where they’re protected from predators.

After my morning visit, I return to Bitter Lake NWR about dusk. I immediately hear the bugles of hundreds of Sandhills gathered on the far side of the pond. I was disappointed, afraid that I had missed the fly-in. But as I took photographs, I heard another flock coming in from the west. They flew straight overhead, dropping in altitude to land—kicking their feet outward to make space. Over the next few minutes, more and more birds arrived, adding to the controlled mayhem of the evening roost.

I was surprised that I was the only photographer there that day. I’ve been to see the Sandhill Cranes at the Bosque del Apache National Wildlife Refuge several times. Nearly due west and over the Capitan Mountains, the Bosque del Apache NWR is located on the Rio Grande and is a mecca for wildlife photographers. You stand tripod to tripod, vying for that “pristine nature” shot. But here, at the Bitter Lake NWR, I’m alone.

What I didn’t realize was that I saw something quite extraordinary. There are two subspecies of Sandhill Cranes that overwinter in New Mexico. The Greater Sandhill Crane (Grus canadensis tabida) spends the winter on the Rio Grande at the Bosque del Apache NWR. The Lesser Sandhill Crane (Grus canadensis canadensis) congregates at the Bitter Lake NWR on the Pecos River.

In the spring, the Greater Sandhill Cranes migrate to their breeding grounds in the Rocky Mountain region while the Lessers keep flying northwest, headed for western Alaska and Siberia.


During the day, Sandhill Cranes forage in tilled fields.

Sandhill Cranes Forage for Waste Grains and Bugs in Farm Fields

I watch the Sandhill Cranes take off at sunrise, flying south along the river. “Where do they go?” I asked Bill Flynt, the Visitor Center volunteer. “Head out the Old Dexter Highway,” he told me. “You’ll find them in the farm fields out there.”

I followed the birds south and, just as predicted, found them feeding in a tilled field. Sandhill Cranes feed on seeds, grains, grasshoppers, and pillbugs. I suspect that before the conversion of grasslands to farm fields and desert scrubland, the Sandhills lived primarily on grass seeds and grasshoppers. But these days, they’re dependent on domestic crops such as waste grain or corn left in the fields after harvesting.  They’ll also eat sorghum and sprouting alfalfa which can be a problem for the farmers.

As the local dairy industry grows, the traditional corn and grain crops are replaced by alfalfa, causing a decline in the overwintering populations of Lesser Sandhill Cranes at the Bitter Lake NWR. Refuge scientists believe that the birds are simply moving on as they deplete their local food resources.

Black silhouettes against the evening sky, Sandhill Cranes return for the night.

The Evening Fly-In

My last evening at the refuge, I watch as the Sandhill Cranes begin to fly in. Their loud bugles can be heard for miles. Sometimes I hear them coming long before I can spot them in the sky. This time, they settle far out in the middle of the ponds. I can see them, I can hear them, but I can’t photograph them. That’s okay. It’s time just to sit and watch this amazing wonder of nature.

Also posted in Birds, Chihuahuan Desert, New Mexico Tagged , , |

Ghosts of the Past: Marine Fish on Mimbres Pottery

Porpoise on Mimbres Bowl from the  Deming Luna Mimbres Museum, New Mexico

In the far southwestern corner of New Mexico is a treasure. The Deming Luna Mimbres Museum, housed in the 1916 Armory Building, has collections that include a lot of just about everything. Who knew someone collected buttonhooks and that they could be so interesting? This is the thing about the museum: it’s easy to get distracted.

I visited on a windy, cold, spring day last week with pretty much one goal in mind. I’d heard about their collection of Mimbres artifacts and, as an archeologist, I just couldn’t resist an exhibit like that. I got a bit lost in the doll collection (there wasn’t a way out), wandered past cabinets of porcelain and fine china, meandered down a narrow hall, and then took a left into a room of wonders. Glass cases held ceramic bowls, pots, and bean jars of all shapes and sizes, trays of tiny beads, arrowpoints, bone tools, and fragile cord used for snare traps. I made the rounds, once, twice, and then just stood there, listening to the stories whispered by the pots.

The Mimbres Room, Deming Luna Mimbres Museum, New Mexico

The Mimbres people lived in the Mimbres River valley of southwestern New Mexico. For about 200 years (between AD 950 and 1150) they produced distinctive black-on-white pottery that told the story of their lives—men setting snares and carrying rabbit sticks, women giving birth, and people swimming with a school of fish. Many of the bowls have a single animal carefully painted on the bottom: a frog, bird, pronghorn antelope, or fish.

At first, you think that the animals are simply abstractions, the essence of the animal. But when you look closer, you begin to notice details and you eventually realize that the little fat bird with the tear-drop shaped circle around its eye must be a Montezuma Quail. Which is interesting, because Montezuma Quail don’t occur in that region today. But neither do the fish.

Quail BowlMontezuma Quail

Stephen Jett, a geographer from the University of California, Davis and his colleague Peter Moyle, a fisheries biologist, got interested in the fish represented on Mimbres pots and wrote a paper titled “The Exotic Origins of Fishes Depicted on Prehistoric Mimbres Pottery from New Mexico” (American Antiquities 51(4), 1986, pp 688-720).

About 11% of the animals shown on Mimbres pots are fishes and, as early as the 1950s, researchers noted in passing that many of the fish weren’t what you’d find in the Mimbres River. In fact, they kind of look like something you’d see in the ocean. But as any geographer will tell you, southwestern New Mexico is a long way from the ocean. A very long way away.

Jett funneled every fish image that he could find to Moyle and asked a simple question: What do you think this is? Surprisingly, Jett and Moyle discovered that they could identify many of the fish and that the majority of the fish species painted on Mimbres pots were marine in origin. Jacks, giant jewfish, snappers, grunts, and the distinctive long-nosed butterfly fish were carefully painted by the Mimbres. The Pacific razorfish—with its distinctive “unicorn” fin—is clearly depicted along with tiny blennies, and giant parrotfish.


Of course, the million dollar question is “How in the world did the Mimbres people know what long-nosed butterfly fish and Pacific razorfish looked like?” But before we answer that question, there’s more you should know.

The Mimbres were apparently fascinated by the ocean. Dozens of clam shell bracelets and hundreds of tiny shell beads fill the trays and cases of the Mimbres rooms at the Deming Luna Mimbres Museum. Thousands of shell items—from at least 11 genera of seashells—have been recovered from Mimbres archeological sites in the region.

Ancient seashells found in a Mimbres site in southern New Mexico.

Conventional wisdom is that all of the shell jewelry originally came from the Hohokam, a contemporary cultural group that lived in south-central Arizona and were believed to control the shell trade. They obtained their raw materials from the Gulf of California and the Pacific coast, ground the shell down to create bracelets, tinklers, pendants, and beads, and then traded them to the Anasazi to the north and the Mimbres to the east.

But Jett and Moyle weren’t quite so quick to accept conventional wisdom. The fish on the pots, they say, indicate that the Mimbreños were very familiar with the ocean and were most likely active participants in shell collecting and transportation. By looking at the species of fish and the types of shell, they concluded that the Mimbres people were making trips to the Gulf of California and specifically, the area around Guaymas, Mexico. Near Guaymas both the reefs necessary for the fish species depicted on the pots and the sandy beaches where the shells could be collected are found.

To the modern human, the thought of walking 1000 miles or so to the coast and back is a bit daunting. But to the Mimbreños? Probably not so much. A trip of that distance would only take a couple of months by foot and there were undoubtedly villages (and trade opportunities) along the way. The marine archeologist in me also has to wonder if they used canoes or some type of water transportation to speed up the journey (although I couldn’t find any images of boats on the pottery I saw).

Because there’s little evidence that the Mimbres people either traded their pottery or imported pottery from other places, they must have painted their fish pots when they returned home. Did they sketch the different types of fish on pieces of bark and take them back to show the potters? Or did they memorize details to paint later?

The pots in the museum whisper to me, but they keep some secrets to themselves.

Deming Luna Mimbres Museum | 301 S. Silver Ave., Deming, New Mexico | 575.546.2382 |


Jett, S.C. & P.B. Moyle. 1986. The exotic origins of fishes depicted on prehistoric Mimbres pottery from New Mexico. American Antiquities 51(4):688-720.

Parks-Barrett, M.S. 2001. Prehistoric Jewelry of the NAN Ranch Ruin (LA15049), Grant County, New Mexico. Master’s thesis, Department of Anthropology, Texas A&M University.

Images from the collections of the Deming Luna Mimbres Museum.

Also posted in Animals, Archeology, Chihuahuan Desert, Fish, New Mexico Tagged , , , |

Places: Dinosaur National Monument, Utah

A two-story wall of dinosaur bones enthralls visitors at the Dinosaur National Monument in Utah.

I received the best news this morning. I feel kind of like the kid that really, really wanted a pony for Christmas. He unwraps his biggest, best-wrapped package to find nothing but a box full of horse manure. He’s insanely, wildly happy. “But you only got manure,” his sister points out.

“Yeah, but where there’s poop, there’s got to be a pony!”

My exciting package was an email that had been forwarded about a million times, but when I dug through the poop, I found the pony. A link—a simple little blue-underlined link—that led to a press release about Dinosaur National Monument in Utah.

Dinosaur National Monument and I go back a long way. My prized possession in the third grade was a fossil clam. Embedded in a limestone slab that I found in the creek on my great-aunt’s ranch in Texas, that clam and I moved around the world together.

In the 5th grade, I spent my time after school sifting through the bulldozed soil of construction sites in our neighborhood looking for pretty rocks and fossils. I found a trilobite one time. I was enthralled by this marble-sized, dark grey animal, curled up like a pillbug. I took it to school the next day and my 5th grade science teacher tried to take it from me. “It will go into a museum,” he said. Even as a 5th grader, I was skeptical of this story. I’d seen the gleam in his eye, the way his hand curled possessively around the trilobite. The trilobite returned home with me and I never showed it to another adult.

After graduating from high school, I traveled with my grandparents from Oregon to Texas. We stopped briefly somewhere in Wyoming or Utah where they were excavating a dinosaur. “Do you want to stay?” my grandfather asked.

“Yes.” I began unloading my luggage from the car.

“No, no,” my grandfather grabbed my arm. “I was just teasing. Let’s go.”

I would have stayed. I probably should have stayed. I think I pouted all the way through Colorado.

My first real brush with Dinosaur National Monument was in 2006 when a friend and I stopped to see the famous wall of bones. We didn’t get far. The quarry was closed for renovations. Come back later. Have a nice day! Damn.

For 150-million years, these dinosaur bones have been sealed in layers of rock.

For 150-million years, these dinosaur bones have been sealed in layers of rock.

Even though I’ve had a life-long obsession with fossils and dinosaurs and things preserved in rock, it wasn’t until 2015 that I actually got to see the Carnegie Quarry at Dinosaur National Monument. I arrived promptly at 9:00 in the morning, road the first tram of the day to the (newly renovated) Quarry Exhibit Hall, and stepped from the bright sunshine to face The Wall. I felt like I was in the presence of God. My heart beat rapidly and I couldn’t quit smiling.

The Wall is a 2-story rock face preserving the story of life approximately 150 million years ago. The rock from nearly 1,500 fossilized bones of long-necked sauropods, predatory theropods, spike-tailed Stegosaurus, and small, but speedy ornithopods was painstakingly chiseled away so the bones would be easier to see.

Although the dinosaur bones get the most attention, it’s the details that tell the story the best. To get the big picture, scientists looked at microfossils, invertebrate, small vertebrates, fossil soils, trace fossils and pollen to understand the environment in which the dinosaurs lived. Was it humid and hot? Or hot and dry? People assumed that the long necks of the sauropods were for browsing in tall forests of conifer trees. The fern fossils were believed to be indicators of a very wet environment.

But by looking at the details as individual pieces to a larger puzzle—rather than the entire puzzle itself—a different story emerged. Over 225 different types of pollen and spores were recovered from the sediments surrounding the dinosaur bones, indicating a much greater diversity of plants than was first believed to exist. Yes, there were conifer trees, but there was also an understory of ginkgo, cycad-like plants, horsetails, ferns, rushes, and clubmosses.

Dense thickets of horsetails still grow along the watercourses of Dinosaur National Monument, Utah.

It turns out that the long-necked sauropods really couldn’t raise their heads much above hip-level, so the idea of dense forests of conifers with sauropods nipping branches from the treetops lost favor. The Jurassic environment was revealed as a Serengeti-like plain with vast semi-arid fernlands interspersed with clumps of conifers and dense riparian vegetation along the watercourses.

At least, that’s what the scientists think now. The thing about science—the exciting thing about science—is that the story changes and gets refined, as we learn more. Chemist Albert Szent-Gyorgyi is credited with my favorite definition of science: “Science is to see what everyone else has seen, but think what no one else has thought.”

That press release that I received this morning opens the door wide for some new thinking about the dinosaurs of Dinosaur National Monument. For the past two years, paleontologist Dr. Dan Chure and a team of volunteers have photographed the fossils of the Carnegie Quarry, illustrated them, digitized historical records, and consolidated data to create a publicly-accessible Digital Quarry.

For armchair paleontologists like me, or serious academic types, this is an incredible resource. It’s days like these that make paying taxes a pleasure. Congratulations, National Park Service. Well done.



Also posted in Dinosaur National Monument, Fossils, National Parks, Utah Tagged , , |

Ghosts of the Past: Mexican Grey Wolf

Mexican Grey Wolf in the El Paso Zoo, Texas.


I believe in ghosts. They hide in plain sight, urging us to listen to the stories they have to tell.

Ash, a Mexican Grey Wolf paces in her enclosure at the El Paso Zoo. She circles through the shrubs, down a slope and back around the rock-lined pond. She pauses for a few seconds to stare at me and then continues her pacing. Ash may not know it, but she’s one of the last of her kind.

Mexican grey wolves such as Ash and her companion, Ivy, were once common throughout the mountain woodlands of central Mexico,  Arizona, southern New Mexico, and southwestern Texas. Vernon Bailey, in his Biological Survey of Texas (1905) describes the grey wolf as “still common over most of the plains and mountain country of western Texas.” But even in the early 1900s, grey wolves were being hunted by ranchers and professional wolf hunters. Bounties were high and wolf hunting was a profitable business. “There is a strong temptation,” says Bailey, “for the hunters to save the breeding females and dig out the young each year for the bounty, thus making their business not only profitable but permanent.”

Not quite permanent, though. In 1972, Dr. James Scudday published a brief report in the Journal of Mammalogy about two young wolves that were trapped in Brewster County in December, 1970. These were the last grey wolves seen in west Texas and pretty much the last seen in the southwest north of the border.

The Mexican grey wolf was put on the endangered species list in 1976 and captive-bred wolves—descendants of breeding stock captured in Mexico—were used to reintroduce the species to the wild in the Blue Range Wolf Recovery Area of New Mexico in 1998. The recovery program has proceeded in fits and starts. Reintroduction of a predator such as the grey wolf has not been enthusiastically embraced by rural and ranching communities, making it an often contentious political, rather than ecological, issue.

Jason Mark, takes a look at both sides of the issue in his fascinating essay Can Wolves Bring Back Wilderness (Scientific American, Oct. 9, 2015).

“Can we find a way to live with the wolf’s wildness and share space together?” questions Mark. “Can we coexist, and come to see another carnivore as something of an equal, and not just an enemy? Or do we have to control it, and in that control limit its wildness, the very thing that draws us to it?”

Will the Mexican grey wolf always be shimmering and barely visible–a ghost from our ecological past?



Also posted in Animals, Chihuahuan Desert, Texas Tagged , , , |