Following dinosaurs along Colorado's Purgatoire River

More than 1,500 fossil footprints allow you to follow dinosaurs as they walked along a lakeshore 150 million years ago. The dinosaur tracksite, the largest in North America, is beside the Purgatoire River in Picketwire Canyon south of La Junta. Read more

Silky phacelia is a handsome wildflower with a special talent

On soils containing gold, silky phacelia is protected by gold, cyanide and even some arsenic. On soils devoid of gold, it is protected by cyanide. Read more

The paradox of toxic nectar and pollen in death camas

Some species of plant, such as death camas, include toxins in nectar and pollen, presenting a bedeviling paradox. Why attract pollinators and then kill them? Read more

Native Americans domesticated turkeys

Analyses of DNA from turkey bones at archeological sites and from modern samples of wild turkeys throughout their range indicate that the domesticated birds in Central Mexico and the domesticated birds from the Southwest are distinctly different. Read more

Tumbleweeds, despised icons of the West

Although tumbleweeds were familiar icons of the West, they were not native to the West, nor were they growing around the early western towns when they were established. Read more

Gritty plants deter herbivores

A comparison of the control and reduced sand leaves showed that removing sand doubled the damage by a variety of insect and snail herbivores. Leaves with added sand had less damage than the control group. Clearly, snail and insect herbivory is reduced by increasing levels of sand on leaves and stems. Read more

Recreational shooting is incompatible with the purposes of Colorado wilderness areas

It is comfortable to expect that wilderness areas will remain unchanged forever, but that is a naïve notion inappropriate to our times. Read more

Antelope horns milkweeds grow in intermittent streambeds on the Colorado Plateau

Last May, I went to the Maze District in Canyonlands National Park to enjoy its unique scenery unusual natural history. On two epic hikes, we encountered a somewhat rare species of milkweed that has turned out to be unusual. Read more
walls, Bridges and Crevasses in a Global World

Students of Intermediate German discuss the Berlin Wall

Colin Turner’s spray-paint installation is one of the 22 pieces of art displayed in the exhibit “Über Mauern hinweg-Beyond Walls,” now housed at the Media Library of the Anderson Language and Technology Center in the Hellems Arts and Sciences building. Read more

Biocontrol weevil appears out of control

Biological control of pest species evokes both high hopes and deep fears. On the one hand, one might achieve a simple, efficient and economic solution to a problem. On the other hand, the control agent may switch from its intended host to one or several unintended native species. Read more
Painted lady image

A prolonged migration of painted ladies

We have been immersed in a large and prolonged migration of painted lady butterflies. On a small scale, it does not appear to be a migration, for the flight of individual butterflies appears undisciplined and erratic, unlikely to be a purposeful movement to a common destination. Read more
Bears ears

Archaeological treasures in Bears Ears

I have been to the area in Utah now designated as the Bears Ears National Monument many times, and each time I was thrilled with the physical environment, for the canyons are deep and intricately sculpted by wind and water while delicate spires, immense buttes and long, high ridges create a unique, romantic landscape. Read more