SALT LAKE CITY - Legislation designating 15 new Utah wilderness areas and guiding development in the state's booming southwest corner is being readied for introduction in Congress, but opposition from environmental groups may preserve the stalemate that has long marked Utah wilderness discussions.

The bill by Sen. Bob Bennett, R-Utah, and Rep. Jim Matheson, D-Utah, carves out areas of Washington County for growth and could nearly double the size of St. George, a city closer to Las Vegas than Salt Lake City.

It calls for the sale of up to 25,000 acres of federal land to private developers or the county, gives more public land to a water district and designates corridors for future roads, motorized trails and utilities. It also expands Zion National Park and grants the Virgin River wild and scenic status, the first such designation for Utah.

The plan follows an example set by Nevada's Clark and Lincoln counties, another rapidly growing area.

But environmental groups that were invited to help craft a plan for Washington County maintain they were shut out of critical negotiations in the end. They say the plan safeguards less than 30 percent of the public lands in the county that are worthy of wilderness protection.

"We tried to offer our views to work out something we could all agree upon," said Pete Downing, legislative director for the Southern Utah Wilderness Alliance.

"Their complaint that they were shut out is their own fault," Bennett said in an interview with The Associated Press. "They said, 'These are our nonnegotiable demands,"' then walked when they couldn't get agreement, he said.

Bennett acknowledged, however, that while not strong enough to pass their own proposals, the alliance and other environmental groups are strong enough to defeat legislation - a formula for stalemate that has characterized the Utah wilderness debate for much of two decades.

"They will be among the big losers, because the uncontrolled growth that's going on in that part of Utah is ultimately going to do them far more damage than the solutions laid out in this bill," Bennett said.

While Bennett's bill calls for 15 new wilderness areas in Washington County, many are small and scattered, ranging from as few as 35 acres to no more than 18,290 outside Zion National Park, where an additional 123,743 acres would be designated wilderness.

Conservation groups said land inside Zion park already is protected, while as many as 200,000 other acres in Washington County that are worthy of wilderness protection are omitted.