BILLINGS, Mont. (AP) " Wildlife advocates are urging a federal judge to keep in place an injunction blocking a $57 million irrigation dam and fish passage proposed for the Yellowstone River.
The Natural Resources Defense Council and Defenders of Wildlife say the dam near the Montana-North Dakota border could cause an endangered fish species to disappear from the upper Missouri River Basin.
In court documents filed overnight Wednesday, the groups urged U.S. District Judge Brian Morris to reject the government's request to start construction this year.
Federal officials argue the fish passage is the best hope for the dwindling population of dinosaur-like pallid sturgeon.
Biologists from Montana Fish, Wildlife and Parks say a better option would be removing a rock weir at the dam site.
The weir blocks sturgeon from reaching upstream spawning habitat.
This story has been automatically published from the Associated Press wire which uses US spellings