Description
The Upper Green River is Wyoming’s take on the Serengeti plains of Africa—a natural bottleneck where wildlife move through ancient migratory pathways. In the lower 48’s longest big-game migration, pronghorn and mule deer travel from summer ranges in the Greater Yellowstone’s mountain highlands to winter stomping grounds in the Upper Green’s sagebrush-covered valley.
The Upper Green River site is a stronghold for sage grouse, the West’s signature native game bird that has suffered population declines, which could lead to a potential listing under the Endangered Species Act.
The open vistas of this mountain-to-high-desert ecosystem are rapidly dwindling. Humans are jamming historic migratory corridors and other wildlife habitat with an expanding web of roads, oil and gas wells, pipelines, housing developments and fences.
The region is also the northernmost headwaters of the Colorado River, a seven-state basin that serves 40+ million people with fresh water but struggles with significant decline in natural river flows due to use and shifts in climate.
Why TNC Selected This Site
Escalating levels of human activity in the Upper Green River site threaten to block ancient migratory pathways, severing the routes big-game animals have used for thousands of years. If these species are to sustain healthy populations, they must have access to the valley’s critical winter range. Several species, especially sage grouse and mule deer, are showing signs of sensitivity to disturbances on the landscape. As headwaters to the Colorado River, learning to live with less water in the Upper Green will become an everyday task. TNC believes there are solutions to coping with drought and climate change that can support all water users, including wildlife and natural systems.
What TNC Has Done/Is Doing
TNC is working with private landowners, agencies and NGO partners to protect critical migration routes and the quality of habitat that migrating big game depend on daily. Through conservation easements, habitat treatments and fence conversion, TNC is maintaining these corridors for wildlife to use in perpetuity. TNC is also working with the University of Wyoming, local landowners and other partners to develop creative solutions that maintain agricultural production and landscape resilience in the face of ongoing drought and potential water shortage in the upper Colorado River Basin. By demonstrating how water users can continue to function as water supply decreases, we can help Wyoming learn how to cope in a drier future.
Contact
John Coffman
Western Wyoming Stewardship Director
307-714-3388
jcoffman@tnc.org