Environmentalists in Utah and Colorado have filed a federal suit accusing the U.S. Fish and Wildlife Service of not only failing to protect a rare cactus but not even replying to their petition to protect it.

Habitat of the Pariette cactus could be damaged by an oil and gas drilling project that is set to start in that section of Uintah and Duchesne counties soon, the suit adds.

The suit was filed in U.S. District Court, Denver, by the Center for Native Ecosystems, based in that city, and the Utah Native Plant Society, Salt Lake City. A spokeswoman for the ecosystems group said that even though the plant is found only in Utah, Denver was chosen as the venue because that is the headquarters for the Fish and Wildlife Service region that includes Utah.

According to the Endangered Species Act, posted on the Internet by the Fish and Wildlife Service, the law requires the agency to respond "to the maximum extent practicable" within 90 days to a request to protect a species.

The suit says the groups filed a petition with the agency on April 12 seeking protection of the Pariette cactus as a threatened or endangered species, but Interior Secretary Gale Norton "violated her duties under the ESA (Endangered Species Act) by failing to make a 90-day finding" on the petition.

"Plaintiffs assert that there exists an emergency posing a significant risk to the well-being of the Pariette cactus as a result of the pending BLM proposal to allow intensive oil and gas development" in the habitat, says the action.

Bill Stringer, field manager of the Bureau of Land Management Vernal Field Office, said last May that he believes the cactus is largely inside a designated Area of Critical Environmental Concern. In planning the Castle Peak and Eightmile Flat Oil and Gas Expansion Project, he said, "we're avoiding knowingly going into a place where we might run into" the Pariette cactus.

If a cactus is found, a well could be shifted or the plant could be taken for purposes like replanting, he said. The BLM does not want to approve any action that would harm this variety, he said.

Newfield Energy, successor to Inland Resources Inc., had proposed to drill about 970 wells, Stringer said. But because of the impact of the project, the BLM drafted an alternative of about 920 wells.

"The project would double the number of wells and surface in the Pariette cactus habitat," the suit says. "The Pariette cactus will lose habitat and be subject to additional roads and off-road vehicle impacts as a result."

Complicating the issue is confusion, at least in the past, over whether the Pariette cactus actually is a species and not just a variety or hybrid.

This type of cactus is found only in a 3-by-10-mile area near Myton Bench in the two counties. According to the suit, it was once believed to be a distinct form of the Uinta Basin hookless cactus.