Conservation groups are suing federal agencies to challenge their approval last year of a proposal by Gunnison Energy to drill 35 oil and gas wells across some 35,000 acres of the upper North Fork Valley.

The groups say the Bureau of Land Management and U.S. Forest Service violated federal laws by failing to properly assess the climate impacts of the project or analyze alternatives that would have minimized environmental impacts.

The suit was brought by the Western Environmental Law Center, on behalf of the Center for Biological Diversity, the Carbondale-based Wilderness Workshop, WildEarth Guardians, Citizens for a Healthy Community in Paonia and High Country Conservation Advocates in Crested Butte.

The project’s location is in Gunnison and Delta counties west of McClure Pass. Some 25,800 acres of the affected acreage is U.S. Forest Service land, 8,648 acres are private and 468 involve BLM land.

The company plans to drill wells down and then out horizontally into the Mancos shale formation from five well pads, three of them new. It has estimated the project could produce up to 700 billion cubic feet of gas over 30 years. That equates to about 2.5% of the gas consumed in the United States last year.

The project also would require about 21 million gallons of water to hydraulically fracture each well, the company has estimated. And conservation groups said in a news release that it would result in about 52 million tons of greenhouse gas pollution, which they said is the same as what a dozen coal-fired power plants emit in a year.

“We are in a megadrought in the North Fork Valley and the Western Slope. The water used to frack in the watershed risks precious water resources and only exacerbates the climate and the water crisis,” Natasha Léger, executive director of Citizens for a Healthy Community, said in a news release. “This 35-well project is the beginning of much larger plans to extract a resource that should be left in the ground and for which the market is drying up.”

BLM and Forest Service representatives on Tuesday declined to comment on the lawsuit. Gunnison Energy could not be reached for comment.

According to the lawsuit, “There remains a fundamental disconnect between public land management for energy production, particularly in the West, including public lands in the (BLM’s Montrose-based) Uncompahgre Field Office and Grand Mesa-Uncompahgre-Gunnison National Forests, and the scientific consensus on the climate crisis and what must be done in the near future to mitigate its worst effects.”

It said the West is particularly susceptible to the effects of climate change, experiencing increased temperatures and prolonged droughts. Gunnison County has warmed more than 1.5 degrees Celsius, and Delta County, 2.1 degrees Celsius, versus historic levels, the suit says. One degree Celsius is equivalent to 1.8 degrees Fahrenheit.

The suit says that in evaluating the project, the BLM and Forest Service failed take a hard look at methane emissions related to the project. Methane is a potent greenhouse gas. The suit also says the agencies failed to use “tools or methods generally accepted in the scientific community to evaluate the impact” of the project’s greenhouse gas emissions, such as the social cost of carbon and global carbon budgeting.

“These protocols estimate the global financial cost of each additional ton of greenhouse gas pollution emitted into the atmosphere, taking into account factors such as diminished agricultural productivity, droughts, wildfires, increased intensity and duration of storms, ocean acidification, and sea-level rise,” the suit says.