LANDER -- A prominent environmental group is trying to stop the construction of new roads and new drilling pads on the Jonah natural gas field in western Wyoming.

The Laramie-based Biodiversity Conservation Alliance filed a lawsuit in the U.S. District Court of Wyoming on Tuesday in an attempt to protect native wildlife -- such as the declining sage grouse population -- in and around the 40-square-mile Jonah gas play south of Pinedale.

"What we want to say to the BLM with this lawsuit is 'never again,"' said Erik Molvar, a wildlife biologist with the conservation group. "Never again should this agency approve such a destructive oil and gas development that so completely flies in the face of multiple use."

The federal Bureau of Land Management was wrong in 2006 when it approved "extreme-density drilling" in the Jonah field, the group is arguing.

In a media release on Tuesday, Molvar claimed the intensity of the approved drilling would "create a wasteland of over 30,000 acres of land in the Upper Green River Valley."

There is "no excuse," Molvar said, for the BLM's decision to allow the so-called extreme-density drilling -- when directional drilling is a reasonable alternative.

Directional drilling is a technique where operators drill multiple wells in multiple directions from a single pad. The practice causes less overall damage to soil and plants as compared to the harm inflicted by the traditional one-well-per-pad approach.

"The well pads will virtually touch each other across 30,000 acres, wiping out key habitats for sensitive sagebrush songbirds, the rare pygmy rabbit and the critically imperiled sage grouse," Molvar said.

On the nearby Pinedale Anticline gas field, most wells are drilled directionally, with up to 32 wells on each pad, Molvar argued.

"We're asking the court to halt the construction of additional roads and well pads, but to permit drilling of new wells on well pads that have already been built, using directional drilling," Molvar said. "If EnCana would have kept drilling directionally from the locations they already had, they could have produced the entire gas deposit with very little additional impact on wildlife and the public lands."

EnCana is the largest producer of natural gas in the Jonah field.

But an industry representative argued that the BCA's claims are misleading. And the current approach to developing the field will actually be better for the environment in the long term, he argued.

Randy Teeuwen, spokesman for EnCana Oil and Gas Inc., said the working area of the Jonah field is about 24,000 acres -- not 30,000 as the BCA claims -- and operators cannot disturb more than 14,030 acres at any given time.

Once the drilling is complete, the area and habitat that was disturbed is reclaimed by law, he said. Plants and grasses are regrown and the natural habitat is reconstituted, he added, all the way up to the well head.

As for directional drilling, EnCana does have the technical expertise to do it, Teeuwen said, but the company has good reasons for vertically drilling the field instead.

"One reason, which is significant, is it takes us less time to drill the vertical wells," he said. "And because of that, it saves the emissions from the operations that are associated with drilling."

The reduced drilling time, in combination with the use of natural gas-powered rigs, lessens overall nitrogen oxide emissions by about 85 percent, Teeuwen said.

"The whole vertical drilling issue is something that (the) Biodiversity (Conservation Alliance) has chosen to disregard in terms of the benefits it has environmentally," he said.

"It is a highly dense drilling operation, but we feel it is our responsibility to extract as much of that gas as possible while we're there, for the benefit of the American public, and reclaim that land."

In a matter of years, Teeuwen said, the land will "be back to pretty much its original condition," and the field will also continue to produce natural gas for perhaps another 40 years.

"I think it's really important to consider what is at stake long term," he said. "We're going to be providing gas to heat homes across the nation for a long time, but in the span in a relatively short period of time that land will go back to where it started."

Additionally, the company has agreed to pay $24.5 million for what is called off-site mitigation, where for every acre disturbed on the Jonah field, there is a two-acre habitat improvement or conservation project completed somewhere nearby, Teeuwen said.

Merry Gamper, a natural resource specialist with the BLM's Pinedale Field Office, said she hadn't yet heard the details of the lawsuit on Tuesday.

The BLM decided to allow denser well pad spacing in 2006, she said, as part of a larger, "aggressive, accelerated reclamation project."

The operators are drilling faster to get to the reclamation phase sooner, she said, and well pads are generally gone and habitat reclamation begun within two months of drilling.

Rev. Warren Murphy, director of the Wyoming Association of Churches, said his group is not part of the lawsuit, but it supports the BCA's attempts to halt new construction on the Jonah field.

"The Wyoming Association of Churches is dedicated to protecting the unique social and natural heritage of the state of Wyoming. We refer to this calling as 'stewardship,"' Murphy said. "The Bureau of Land Management, which is called to be a steward of these lands as well, has often replaced stewardship with the desire to drill more and more. It is time to slow down the process so that we can ask ourselves the question of how much we want to sacrifice."