146 days, 8,087 specimens and a mountain full of surprises

Young botanist uncovers the Big Horns’ hidden flora

For more than 160 years, botanists, explorers, ranchers, hunters and hikers have traveled the Bighorn Mountains. Generations have crossed their canyons, wandered their meadows and climbed their highest peaks.

You might think by now we would know about everything that grows there. Daniel J. Coles discovered otherwise.

For parts of three summers, Coles worked on one of the most extensive botanical inventories ever completed in the Bighorn National Forest. The work eventually became his 2026 University of Wyoming master’s thesis, A Comprehensive Vascular Floristic Inventory of the Bighorn National Forest, Wyoming.

The numbers alone are impressive. The project included 146 days of fieldwork and produced 8,087 plant specimens. When Coles’ works was combined with verified historical collections, researchers documented 1,117 plant taxa in the forest. More than 200 had not previously been documented there, along with rare Arctic plants, new non-native records for Wyoming and one non-native species never before documented growing wild in North America.

But behind those numbers is a much more personal story involving long hikes, heavy backpacks, lonely nights in a tent and a young Wyoming botanist learning the Bighorns one canyon, meadow and mountaintop at a time.

Coles grew up in Cheyenne and attended the University of Wyoming, where he first earned a bachelor’s degree in wildlife and fisheries biology and management.

By his final semester, however, he began questioning whether wildlife was really where his interests belonged.

He had enough educational funding remaining to pursue another degree, so he added a second bachelor’s degree in botany. That decision changed his direction. “I really got into invasive plants,” Coles said.

His work eventually connected him with the Rocky Mountain Herbarium at UW, which offered him an opportunity to help inventory the plants of the Bighorn National Forest. “I was like, yeah, I’ll definitely do this,” he recalled. “That’s fun.”

Fun, however, sometimes meant carrying a 65-pound backpack through the Cloud Peak Wilderness.

Coles had done some overnight trips in Wyoming’s Snowy Range before graduate school, but he did not consider himself an experienced long-distance backpacker. He quickly learned.

During his field seasons, Forest Service ranger stations served as base camps. He stayed at the Shell Ranger Station one summer and the Hunter Ranger Station near Buffalo another.

From there he traveled throughout the forest looking for plants in different habitats and elevations.

Early in the growing season that meant lower country. As summer progressed, the work moved higher into the mountains. By mid-July, much of Coles’ attention turned toward the Cloud Peak Wilderness, one of the least thoroughly collected botanical areas in Wyoming.

Trips there often lasted four or five days. Coles carried food, camping equipment and the materials needed to collect plants, including newspaper and cardboard for pressing specimens.“All too many to count,” he said when asked how many nights he spent alone in a tent.

The work was systematic rather than simply wandering around picking flowers. Researchers examined historical collecting maps, topographic maps, satellite images and different habitat types to decide where additional collecting was needed. Coles personally completed 106 collecting days during the 2024 and 2025 seasons. Some survey routes stretched as far as 12 miles.

He was also trying to beat the clock. At high elevations, plants may bloom and disappear quickly. “Once you get into the Cloud Peak Wilderness, those things go by so fast,” Coles said. “In my experience, most wildflower species were done within a week.”

Some of his most interesting finds came near the highest peaks, where isolated populations of rare Arctic plants survive in cold alpine environments far removed from their primary ranges.

Those discoveries helped document five rare Arctic disjunct plants not previously verified in the forest.

Then came the discovery Coles called the greatest botanical find of his career. In Little Horn Canyon he found snowdrop anemone, Anemone sylvestris.

The plant is native to Eurasia and endangered in portions of its native range. In the Bighorns, however, it appears to be an introduced species.

More remarkably, Coles’ collection represented the first documentation of the species growing wild in North America.

He believes it may have arrived through human settlement or landscaping, possibly associated with summer cabins in Little Horn Canyon.

The discovery illustrates one of the unusual questions botanists sometimes confront. A plant can be rare and protected in one part of the world while potentially invasive somewhere else.

The mountains also produced another tantalizing mystery. Near Tensleep, along the forest boundary, Coles collected a mustard that he and other botanists could not confidently match with any known regional species.

Samples were sent to a North American expert for genetic analysis. It could potentially represent an undescribed native species. For Coles, the Bighorns were also more than a laboratory.

He fly-fished mountain lakes and streams when time allowed and explored country few people ever see. In the Cloud Peak Wilderness, he said, he was impressed by how little litter he encountered.

“I hardly ever found any sort of trash, like ever,” he said. His experience also reinforced just how botanically varied the Bighorns are.

The western slope near Lovell, Shell and Tensleep is considerably drier than the eastern side of the range. Coles describes a “double rain shadow” that helps produce dramatically different environments on opposite sides of the mountains.

Western canyons such as Shell, Tensleep and Devils Canyon are influenced by the dry Bighorn Basin and contain combinations of plants different from much of the rest of the forest.

At the opposite extreme are the alpine environments near Cloud Peak, which rises more than 13,000 feet and still holds the Bighorns’ last remaining glacier.

Despite more than a century and a half of botanical collecting, the ruggedness of the mountains left surprising gaps in scientific knowledge. Coles’ thesis notes that steep terrain, limited access, windfall, poor trails and nearly 9,000 feet of elevation change have discouraged systematic collecting in some remote areas.

The first known botanical specimen collected within today’s Bighorn National Forest dates to August 1859, when Ferdinand Hayden collected a plant near the headwaters of the Tongue River. Later botanists including Aven Nelson and others gradually added to that record.

More than 160 years later, Coles added thousands more specimens to that scientific history.

He dedicated the finished thesis to his grandmother, Shirley V. Coles, and his late grandfather, Thomas J. Coles, who adopted him when he was very young.

Coles credits them with helping create his love of the outdoors. “They really let me explore the outdoors,” he said.

When life was difficult, the outdoors became a refuge. “If I was ever struggling or anything, I’d go explore the outdoors,” he said.

His grandfather died just days before Coles was scheduled to begin his second field season, forcing him to delay his return to the mountains. “I wouldn’t be where I’m at in life today if it wasn’t for them,” Coles said.

Today Coles is working as a biological science technician for the Bureau of Land Management in Lander, but he is not finished with the Bighorns.

He continues returning when opportunities arise to work with other botanists on rare plant surveys.

Perhaps that is appropriate. After thousands of specimens, hundreds of miles of hiking and summers spent searching from dry western canyons to windswept alpine peaks, Coles’ research reached an encouraging conclusion:

The Bighorns are still not completely known. There are still plants to find, places to survey and perhaps even species awaiting discovery.

For anyone who loves the mountains, that may be one of the most exciting findings of all.