Two environmental groups have given notice they plan to file a lawsuit to stop a proposed underground natural gas pipeline from Idaho to Wyoming.
The groups say it will harm protected grizzly bears and other wildlife.
The Alliance for the Wild Rockies and Yellowstone to Uintas Connection sent a required 60-day notice to sue this week to the U.S. Forest Service and U.S. Fish and Wildlife Service.
The groups contend the approval of the pipeline project in November violated the Endangered Species Act.
They say an 18-mile portion would cut a corridor through the Caribou-Targhee National Forest and areas designated as roadless.