A citizens group and a chapter of the Sierra Club are accusing the U.S. Forest Service of putting a "mountain jewel" in harm's way.

In a lawsuit filed this week, the organizations said the agency's authorization of Alta Ski Lifts Co. construction projects in the Albion Basin "will irreversibly change the character of this cherished landscape."After months of study and contentious public debate, the Forest Service last year gave Alta Ski Lifts the green light for trail modifications and snowmaking lines on Roller Coaster, Devil's Elbow and Crooked Mile ski trails and realignment of Sunnyside lift.

According to the suit, the project will require "bulldozing 55 acres of alpine meadows, filling in 150 feet of perennial stream beds with boulders, blasting geologically significant glaciated rock surfaces and cutting nearly 100 mature Engelmann spruce and alpine fir trees."

The action was filed in U.S. District Court by Citizens' Committee to Save Our Canyons, Salt Lake Group of the Utah Chapter of the Sierra Club, Gale Dick, Alexis Kelner and Ann Wechsler. It seeks an order vacating the Forest Service's approval of the project and a requirement that the agency comply with federal environmental procedures before granting another permit.

Also, the groups want the Forest Service to consider alternatives to the Albion Basin work and prepare a single areawide environmental impact statement covering all pending ski resort construction and expansion projects at Alta, Snowbird, Solitude and Brighton Ski Resorts.

A Forest Service spokeswoman said agency officials had been forewarned about the lawsuit but had not seen it. She said the agency would have no comment until government lawyers have a chance to review the specific allegations and demands in the lawsuit. Alta Ski Lifts officials could not be reached for comment.

Located at the top of Little Cottonwood Canyon, Albion Basin is a scenic, two-square-mile glacial cirque with hiking trails and a Forest Service campground that attract an estimated 180,000 visitors during the summer and fall months.

"Albion Basin is so scenic and popular as a summer destination that is considered to be one of the chief ornaments enhancing the attractiveness of the Salt Lake area as a place to live and visit," the suit said.

It also contains part of the Alta ski area, which has led to a "gradually escalating conflict between summer and winter use," the suit said. When the Forest Service invited comment on its draft environmental impact statement in 1996, it received more than 300 responses.

Despite vocal opposition, the Forest Service approved the bulk of Alta Ski Lifts' plan on Nov. 24, 1997. Opponents appealed the decision earlier this year but lost in the administrative arena. The battle has now moved to federal court.

The opponents said they had suggested reasonable alternatives, including one that would expand the work on Lower Devil's Elbow and leave Roller Coaster untouched.

"By the U.S. Forest Service's own admission, the agency did not develop and study either an alternative that would protect the unique qualities of Albion Basin or an alternative which would implement aspects of the Alta Ski Lifts projects without creating significant environmental effects," the suit said.

According to the suit, the Forest Service was "improperly influenced and artificially constrained" by its adoption of Alta Ski Lifts' statement of purpose and need for the project.

The statement, which was incorporated in the Forest Service's final environmental impact statement, said the purpose of the project was to "allow private enterprise to accomplish needed high capital investment recreation opportunities" and to "meet demand for downhill skiing by allowing additional facilities within permitted areas."

Opponents also contend that the Forest Service should consider all the pending projects at the four Little Cottonwood Canyon ski resorts in a single environmental impact statement.

"The ski resort development projects at Brighton, Snowbird, Solitude and Alta have very close timing and geography . . . and these development projects and plans will have combined impacts on wildlife, wildlife habitat, wetlands, air quality, soil stability, water quality in the Salt Lake City watershed, recreation, socioeconomics and the visual quality of the region," the lawsuit said.