Wildlife advocates say an endangered, dinosaur-like fish is at risk of being eliminated from key habitat in two rivers in Montana and North Dakota because of dams that disrupt spawning.
Defenders of Wildlife and the Natural Resources Defense Council on Monday filed a lawsuit asking a federal judge in Montana to order new steps to protect pallid sturgeon.
Representatives of the groups say Fort Peck Dam on the Missouri River and Intake Diversion Dam on the Yellowstone River prevent sturgeon from successfully breeding.
The suit names several federal agencies as defendants.
Pallid sturgeon can live up to 50 years and reach up to 6 feet in length. They survived millions of years before a series dams built along the Missouri River system drove them into decline.