Migration Corridors

First Lite Banner Go Farther Stay Longer

Wyoming’s ungulates – deer, pronghorn, elk, and moose- are on the move. Following patterns of weather, elevation, and food availability over eons has led to large groups of animals moving from low elevation areas in the winter to higher elevations in the summer. Spring migration offers animals the youngest, tenderest, and most nutritious plant growth at a time when extra energy is needed to produce the next generation. The reverse pattern allows the animals to minimize energy as they forage in deep snow conditions. These annual migrations are why Wyoming’s harsh winter landscapes can support the vast herds of ungulates we value today. The seasonal routes allow animals to move from summer to winter range and are critical to maintaining these herds.

Wild ungulates in this region have been following their migration paths for millennia. Today the potential impacts on these paths can impact the long-term health of these herds. Some issues are simple barriers, like fences. Others are more complex, like rural development, new roads, and energy development. These do not stop the animals physically but, alter the landscape to the extent few animals are willing to pass through. These semi-permeable barriers can also compromise stopover habitat; the rest stops on the migration routes animals use to refuel and rest along their journey. Bottlenecks, areas of migration routes where many animals pass through a very narrow band of habitat, also need protection. Disturbances in bottlenecks can put the entire migration at risk of being cut off.

The migration routes of ungulates across Wyoming are part of our natural heritage. They are part of what makes our state so wealthy in wild ungulates. Conserving these corridors while reducing and eliminating barriers to migration ensures that we will have healthy herds for the coming years and the next generation.

WHY DON’T ANIMALS MIGRATE SOMEWHERE ELSE?

Many animals, including ungulates, follow patterns of weather, elevation, and food availability moving from low elevation in winter to higher elevations in summer. This pattern, following young grasses and forbs, is called “surfing the green wave.”

In spring animals make use of the youngest and most nutritious plant growth. At this time extra energy is crucial to producing the next generation. The reverse pattern allows animals to minimize energy use while traveling in deep snow conditions. This movement pattern dictates a herd’s migration corridor. These are not point-to-point journeys but are vital habitat areas ensuring the survival of Wyoming herds. Animals spend almost 1/3 of their lives, when they are most vulnerable, on these corridors and pass this food knowledge to the next generation.

Current Migration Corridors of Interest

Red Desert to Hoback Corridor

Red Desert to Hoback

Mule Deer Migration Corridor

Length: 160 miles Area: 624,771 acres
Herd Population: 24,200 animals
Sage Grouse Core Habitat: 322,883 acres
Critical Seasonal Mule Deer Habitat: 190,742 acres
Critical Pronghorn Habitat: 43,297 acres
Critical Elk Habitat: 211,048 acres

This mule deer migration route is the original migration that revealed the importance and the extent of ungulate migration corridors. It is the longest mule deer migration corridor in the world. This route parallels the Sublette pronghorn migration, ranging from the low-elevation winter ranges in the Red Desert to the high mountain slopes surrounding the Hoback Basin. The corridor runs through Bridger-Teton National Forest and BLM land as well as numerous private holdings. It is relatively free from historical oil and gas development with only 134 existing wells in the corridor. This is likely one reason for the length of the corridor and its consistent high-use. Recent efforts by WWF and others have deferred parcels within the corridor marked for development. The corridor is impacted by state highways 28, 191, and 189, with highway 28 bisecting the corridor at a narrow point.

Wyoming Range Corridor

Wyoming Range Mule Deer

Mule Deer Migration Corridor

Length: 130 miles Area: 1,347,621 acres
Herd Population: 34,500 animals
Sage Grouse Core Habitat: 235,266 acres
Critical Mule Deer Habitat: 414,446 acres
Critical Pronghorn Habitat: 46,798 acres
Critical Elk Habitat: 493,715 acres
Rather than a single path, the Wyoming Range mule deer migration corridor is a highly braided set of routes that deer use to pass between the Hoback Rim above Bondurant south to Kemmerer. The corridor crosses two mountain ranges, the Salt River Range and the Wyoming Range. The primary management agencies for this corridor are National Forest Service and the Bureau of Land Management (BLM). There are 1,531 existing oil and natural gas wells in the corridor, which has been affected by human resource development for almost 100 years. The corridor is impacted by Wyoming state highways 30, 89, 189, and 232.

Recent efforts by WWF and others have deferred parcels within the corridor marked for development. The corridor is impacted by state highways 28, 191, and 189, with highway 28 bisecting the corridor at a narrow point.

Platte Valley Corridor

Platte Valley Mule Deer

Mule Deer Migration Corridor

Length: 70 miles Area: 73,234 acres
Herd Population: 10,900 animals
Sage Grouse Core Habitat: 44,505 acres
Critical Seasonal Mule Deer Habitat: 33,755 acres
Critical Pronghorn Habitat: 17,011 acres
Critical Elk Habitat: 13,078 acres
This corridor is unique. This herd does not move from a single wintering area to a single summering area. Instead, mule deer are moving from various wintering areas in the Platte Valley, Sierra Madres, the Snowy Range, and North Park, CO. The paths are diffuse, but mule deer studied in the region had a high fidelity to their given corridor. This suggests these routes are long-established and unimpeded passage is critical to the movement between ranges. This corridor runs through a mosaic of landowners – mostly private with some BLM included. Unlike corridors in the western portion of the state, this corridor is relatively un-impacted by oil and gas development, with only 2 wells in the corridor area.
In Wyoming, the migration path crosses I-80, a principal threat to deer travel and motorist safety. The corridor is also impacted by state highways 130, 230, and 287.

Sublette Antelope Corridor

Sublette Antelope

Antelope Migration Corridor

Length: 60 miles Area: 305,785 acres
Herd Population: 18,800 animals
Sage Grouse Core Habitat: 185,627 acres
Critical Seasonal Mule Deer Habitat: 94,186 acres
Critical Pronghorn Habitat: 29,666 acres
Critical Elk Habitat: 104,216 acres
The Baggs migration corridor is the shortest of the identified migration corridors in Wyoming, but mule deer use the same path to move from winter range along the Atlantic Rim to summer range in the Sierra Madres. The corridor runs through a checkerboard of BLM and private land. There are currently 137 existing oil and gas wells in the area and proposed leases in the corridor were deferred in 2019, so it is potentially impacted by future oil and gas development. This corridor is also impacted by state highway 789.

Baggs Migration Corridor

Baggs Mule Deer

Mule Deer Migration Corridor

Length: 60 miles Area: 305,785 acres
Herd Population: 18,800 animals
Sage Grouse Core Habitat: 185,627 acres
Critical Seasonal Mule Deer Habitat: 94,186 acres
Critical Pronghorn Habitat: 29,666 acres
Critical Elk Habitat: 104,216 acres
The Baggs migration corridor is the shortest of the identified migration corridors in Wyoming, but mule deer use the same path to move from winter range along the Atlantic Rim to summer range in the Sierra Madres. The corridor runs through a checkerboard of BLM and private land. There are currently 137 existing oil and gas wells in the area and proposed leases in the corridor were deferred in 2019, so it is potentially impacted by future oil and gas development. This corridor is also impacted by state highway 789.

Latest Related News

Pronghorn Red Desert Not Blurry

Hunters First Crack at Western Big Game: A Pronghorn Hunt Story

By Guest Contributor | December 19, 2023

Southern Hunter’s First Crack at Western Big Game A First Pronghorn Hunt Story EDITOR’S NOTE: This hunt occurred in fall of 2022. Since then, this pronghorn herd saw impacts to their numbers from the harsh 2022-2023 winter and there are no pronghorn doe …

Hunters First Crack at Western Big Game: A Pronghorn Hunt Story Read More »

What We Do To Help

Wyoming Wildlife Federation has a number of specific Programs that address this

issue directly. Click on a Program in the list below to explore it in depth.

Wyoming’s roadways see some of the highest rates of vehicle/ wildlife collisions anywhere in the United States. Working to reduce the hazard not only benefits wildlife but, also greatly helps reduce the number of human fatalities and injuries.

Intact and expansive ungulate migrations are unique to Wyoming and the continuation of these animal movements relies on the conservation of key corridors in specific regions of the state.

Bringing hunters and anglers together and building an effective and informed advocacy voice is the mission for the Camo at the Capitol program.

WANT TO HELP FUND OUR WORK? MAKE A DONATION