JACKSON - A five-year project is under way to improve the pronghorn migration route from Sublette County to Grand Teton National Park.

An inventory of 100 miles of fencing along the route was completed last month. The inventory looked at the location, type and condition of fences on 150 properties in the 33 miles from the Bridger-Teton National Forest boundary south to Trapper's Point, north of Pinedale.

The Green River Valley Land Trust in Pinedale is organizing the fencing project. It seeks to improve 500 miles of fence over the next five years to make it easier for antelope and other wildlife to cross. The group hopes to improve the 100 miles of fence between Trapper's Point and the Forest Service boundary before the snow flies this winter.

For thousands of years, antelope have traveled the 350-mile route from their summer range in what is now Grand Teton National Park to winter range as far south as Rock Springs.

Lara Ryan, executive director of the Green River Valley Land Trust, said Enercrest, an energy company, has "adopted" the first mile of fence at a cost of $25,000. The company also performed the inventory.

Ryan said improvements for the entire 500 miles of fence will cost an estimated $10.7 million.

"We created what's called the Adopt-a-Mile program, and the goal was to encourage individuals, groups of friends, businesses, families and others to have a means of getting involved," Ryan said. "There are lots of ways to get involved."

Ryan said her group welcomes smaller donations or donations of labor.

U.S. Interior Secretary Dirk Kempthorne announced a $1 million grant for the fencing project this summer. The money is coming from the Jonah Interagency Mitigation and Reclamation Office. The office, which is funded by the energy industry, was established to mitigate the effects of large-scale energy development in the upper Green River Basin.

Ryan said her group is working to raise $1 million to match the original grant. She said work to improve the migration corridor is a collaboration between state and federal agencies as well as companies and individuals. Officials at the Bridger-Teton National Forest, one of the agencies involved, say they hope to start an inventory of fences in the rest of the pronghorn path next year.