CHEYENNE, Wyo. (AP) — Environmental groups are suing over plans for a potentially huge Wyoming gas field they say would endanger antelope in Grand Teton National Park by hindering a migration route between the park and a basin.

The Upper Green River Alliance, Western Watersheds Project and the Center for Biological Diversity sued the U.S. Bureau of Land Management in U.S. District Court in Cheyenne on Wednesday.

The groups say the agency insufficiently took into account a 170-mile (270-kilometer) pronghorn antelope migration corridor between Grand Teton and the Upper Green River Basin before approving a plan to develop the Normally Pressured Lance gas field in the basin in 2018.

The Jonah Energy project would potentially add 350 gas wells a year to the gas field over a decade. With 3,500 wells, the Normally Pressured Lance field could become one of the biggest onshore gas fields in the U.S.

“This plan would sacrifice Grand Teton’s magnificent pronghorn herd and one of North America’s oldest migration corridors to enrich fossil fuel companies,” Wendy Park, an attorney at the Center for Biological Diversity, said in a statement. “It’s obscenely cruel and shortsighted.”

About 300 antelope migrate between the basin, where they winter, and Grand Teton, where they spend the summer, according to the groups.


The Bureau of Land Management is reviewing the lawsuit but contends it complied with federal law, said Brad Purdy, a spokesman for the agency’s Wyoming State Office.

The development plan calls on Jonah Energy to work with the Wyoming Game and Fish Department when siting wells to minimize disruption of wildlife and migration areas, Purdy added.

The Upper Green River Basin is a major gas-producing area that makes Wyoming a top gas-producing state, though low prices have led to a decline in production over the past decade.

Wyoming’s vast, sagebrush-covered basins are a stronghold for antelope, North America’s fastest land animal. But their numbers have declined to a tiny fraction of the tens of millions that once inhabited the West.


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