By Matthew Brown, Associated Press

BILLINGS, Mont. (AP)  Environmental groups sued Thursday to force the Obama administration to impose more restrictions on oil and gas drilling, grazing and other activities blamed for the decline of greater sage grouse across the American West.

A sweeping sage grouse conservation effort that the government announced last September is riddled with loopholes and will not be enough to protect the bird from extinction, according to the lawsuit filed in U.S. District Court in Idaho.

It follows several legal challenges against the same rules from the opposite end of the political spectrum. Mining companies, ranchers and officials in Utah, Idaho and Nevada argue that the administration's actions will impede economic development.

The ground-dwelling sage grouse, known for their elaborate mating ritual, range across a 257,000-square-mile region spanning 11 states.

The new rules and land use policies for federal lands in the region were meant to keep the popular game bird off the endangered species list. They are backed by more than $750 million in commitments from the government and outside groups to conserve land and restore the bird's range.

But the lawsuit from the Western Watersheds Project, Center for Biological Diversity and two other groups said the rules have too many exceptions favorable to industry at the expense of the bird.

"Each state had its own specific loophole," said Erik Molvar with WildEarth Guardians, another plaintiff in the case. "For Wyoming, there are huge loopholes for oil and gas. Nevada has loopholes for geothermal power. In southeastern Oregon, there were loopholes for wind farms. And everywhere there are loopholes for transmission projects."

Interior Department spokeswoman Jessica Kershaw declined to comment directly on the lawsuit, but she said the government's conservation plans follow the best science and were crafted in partnership with state and local officials.

"The plans are both balanced and effective, protecting key sage-grouse habitat and providing for sustainable development," Kershaw said in an emailed statement.

The grouse population once was estimated at 16 million birds across North America. It's lost roughly half its habitat to development, livestock grazing and an invasive grass that encourages wildfires in the Great Basin of Nevada and adjoining states. There are now an estimated 200,000 to 500,000 greater sage grouse.

The Prairie Hills Audubon Society of South Dakota was another plaintiff in Thursday's suit.

Notably absent was its parent organization, the National Audubon Society. The influential, New York-based advocacy group supports the administration's plans and wants them to be given time to work, spokesman Nicholas Gonzalez said.

To Learn More:

Backed by Big Oil, House Republicans Use Military Bill in Campaign to Keep Sage Grouse off Endangered List (by Noel Brinkerhoff, AllGov)