JACKSON -- Scientists and environmental groups' consultants say a proposal to dramatically increase natural gas drilling on the Pinedale Anticline is rushed and lacks assurances the environment will be protected.

Industry representatives, meanwhile, say the intense, year-round development would allow extraction of gas to be over more quickly, meaning areas could be reclaimed faster. They also say their plans call for use of technologies and practices intended to reduce impact to the environment.

The nearly 200,000-acre Pinedale Anticline is one of the biggest natural gas resources in the country, holding about 25 trillion cubic feet of gas -- enough to heat 10 million homes for 30 years. The area also contains prime habitat for wildlife.

Bill Alldredge, a wildlife biologist formerly with Colorado State University who was asked to review the proposal by conservation groups, said the plan to allow 4,399 more wells on the Pinedale Mesa would result in "massive industrialization" in the heart of mule deer and pronghorn habitat. Alldredge spoke during a Monday news conference organized by the groups.

He also said the Bureau of Land Management -- the agency writing an environmental analysis of the project that is subject to public comment through Friday -- has underestimated impacts in the past and should focus on a less intense, more moderately paced drilling scenario.

The proposal would increase development from 1,139 wells now authorized to 4,399 wells. It would also bump the amount of initial surface disturbance up from 4,484 acres now authorized to 12,278 acres, but in a concentrated strip down the center of the Anticline.

There are now about 500 wells on 348 well pads, scattered on the Mesa. A 2000 decision limits well pads to 245 through 2011, but subsequent BLM decisions have allowed energy companies to bump up those numbers.

Diana Hoff, general manager for Questar's Pinedale division, has said her company, among others, submitted the proposal to BLM to manage the Anticline field into the future, in an attempt to get ahead of development and plan for the effects and the reclamation. She was not available for comment Monday.

Steven Hall, spokesman for the BLM's Cheyenne office, said the proposal aims to consolidate infrastructure including roads and pipelines to disturb as little as possible.

Responding to criticism the document does not go far enough to ensure reclamation is adequate, Hall said the BLM has create new language calling for "course corrections" if reclamation falls short of wildlife's needs.

The BLM's preferred proposal is a tweaked version of industry's proposal. While industry wanted the BLM to waive seasonal stipulations for big game, the BLM's proposal would retain some seasonal restrictions.

But both proposals are similar in that they allow for a massive "core" -- nearly 19 square miles -- of intense development. Areas outside that core would be reclaimed and available for wildlife, habitat fragmentation would be reduced, and companies would institute a liquids gathering system that would eliminate thousands of truck trips onto the Mesa each year.

And, most seasonal stipulations would be waived so companies could drill for natural gas year-round. Currently, year-round activities require special permission, which the BLM has granted in many instances.

Industry officials say year-round drilling would allow for southwest Wyoming communities to plan for the impact of drilling rather than witness the problems associated with seasonal workers. It would also be more stable for companies, as they could maintain a year-round work force and equipment.

Companies coming forward with the proposal include Questar, Ultra Resources Inc., Shell Exploration and Production, Wexpro Co., BP America, Stone Energy and Yates Petroleum.

The BLM acknowledged in its study that the operators' proposal "could cause significant adverse impacts to the human and natural environments." At a recent public open house for the proposal in Pinedale, no one spoke in favor of the BLM's or operator's proposal.

Alldredge said the reclamation proposal falls far short of what is needed to maintain wildlife populations. Reclamation would involve grasses and forbs, rather than the shrubs and other forage more nutritious for mule deer and antelope. And, he said, the current proposal assumes reclamation will be swift, when many scientists believe sagebrush takes 50 to 100 years to reclaim.

"The wheels of ecological succession grind very slowly," he said.

Clait Braun, a sage grouse expert formerly with the Colorado Division of Wildlife, said sage grouse may be hurt the most by the current proposal.

Regulations call for a buffer of at least a quarter mile from sage grouse nesting areas, but Braun said even three to five miles of development around leks is "impactful." He said there needs to be at least a mile buffer, and the core development area will be useless for sage grouse.

He said the birds now on the Mesa will be eliminated from the core development areas, and the rest will eventually leave because of the intense development.

"There really isn't any rational, scientific hope that sage grouse populations are going to persist" on the Anticline under the proposal, he said, calling it a "prescription for extinction."

Sage grouse have been considered for listing under the Endangered Species Act.

Air quality experts said some thresholds will be exceeded under the proposal -- namely, larger particulate matter (a contributor to smog) and nitrous oxides. According to the BLM's document, most air quality impacts would be reduced under the current proposal because of requirements for companies to install tighter emission control measures as development progresses.

Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at royster@tribcsp.com.