ASPEN — The Trump administration is pushing to open more public land in Colorado for fossil fuel development, preparing to sell off access to minerals under 45,000 acres near a state park and bird habitat along the upper Colorado River.

But the intensifying efforts by the federal Bureau of Land Management face resistance.

Conservation groups are fighting in federal court to block this leasing in already-drilled areas around De Beque, accusing the feds of skipping required environmental reviews.

And in southern Colorado this week, Huerfano County commissioners began drafting a formal request to the BLM to delay the proposed leasing of 18,000 acres for oil and gas drilling, including parcels that touch the Sangre de Cristo Wilderness Area and come as close as a mile to the Great Sand Dunes National Park and Preserve. Those officials previously said they’d stay out of that battle.

“All this development is for fossil fuels, which are creating a warmer climate. The BLM has never analyzed and disclosed that connection adequately,” said Peter Hart, staff attorney of Wilderness Workshop, an architect of the legal challenge in federal court. “It requires a huge amount of water. It takes land that is important wildlife habitat, land that provides habitat for threatened and endangered species, rare plants. It takes water out of rivers that fish and people depend on.”

The BLM push in Colorado reflects nationwide efforts under President Donald Trump to use public land to increase oil and gas production. White House officials say this will further reduce U.S. dependence on imported fossil fuels. U.S. companies are exporting more oil and gas after boosting production over the past 15 years. A proposed pipeline and processing plant in Oregon at Jordan Cove has piqued interest in western Colorado for producing more fossil fuels that could be sent to China and elsewhere across the Pacific Ocean.

The feds have been shortening periods for public comment on proposed sell-offs from 30 days to 10 days and relying on a bureaucratic maneuver to lease land to companies without conducting full environmental reviews.

The BLM’s acting state director on Monday wasn’t made available to The Denver Post, but an agency spokesman defended what the agency calls a Determination of National Environmental Policy Act Adequacy (DNA).

“DNAs are used as part of the BLM’s emphasis on energy development and more efficient management of the public’s resource,” Steven Hall said in an email, adding that in such cases the BLM relies on existing land-use plans that factor in industrial impact on the environment.

“The BLM welcomes the input of local governments, local communities and constituent groups in the oil and gas leasing process,” Hall said.

“For some, oil and gas leasing anywhere under any circumstances is unacceptable,” he said. “The recent surge in oil and gas leasing is driven in part by market forces. The BLM responds to demand for oil and gas leasing as part of the BLM’s multiple-use mission, which requires the BLM to offer the public’s oil and gas resources for lease in an environmentally responsible way.”

Environment groups are organizing to oppose what they see as harmful new projects. They contend Interior Secretary Ryan Zinke is pushing development from Alaska to the Gulf of Mexico faster than companies are prepared to conduct exploration. BLM officials keep secret the names of groups that nominate parcels for development.

“This administration is conducting a fire sale of public lands to the oil and gas industry at the expense of U.S. taxpayers,” said Nicole Gentile, deputy director of the public lands program at the Center for American Progress, a liberal think tank. “With no incentive to develop these lands, Trump is aiding oil and gas companies who are prospecting and speculating while the American public is losing out on the right to use these lands for other purposes like hunting, fishing or hiking.”

A 2018 Colorado College “State of the Rockies” public opinion survey found that voters in Colorado and other Western states favor a greater emphasis on protecting public lands than on energy development.

Trump appointees “are doing anything and everything they can to promote accelerated oil and gas drilling on public land. They don’t care about the geology, the climate-change impacts, nature. They just want to lease as much as possible whether there’s oil there or not,” said Athan Manuel, the Sierra Club’s Washington, D.C.-based land protection program director.

“We want to make sure every law is obeyed and that every impact is taken into consideration. There’s no reason to go faster. This is federal land that belongs to all Americans and, before the federal government leases it to private companies, the government should do due diligence. That includes a full environmental impact study.”

The 45,000 acres near the Colorado River include parcels near the James Robb Colorado River State Park, the Highline State Park, a mountain bike racing area north of Fruita, Vega Reservoir fishing and hunting terrain, and towns of De Beque, Molina and Mesa.

In Huerfano County, commissioners’ draft letter to the BLM noted local leaders consulted with Navajo tribal leaders, who recently purchased ancestral land along the Sangre de Cristo Mountains and have vowed to defend the sacredness of the land. The commissioners ask the BLM to defer any leasing until a study of underground water flows is done and until a 27-year-old BLM land-use plan is updated.

Western Energy Alliance president Kathleen Sgamma defended Trump administration actions as “merely moving forward with leasing on public lands already designated as appropriate for leasing” under existing land-use plans.

“We’re optimistic that the (Jordan Cove natural gas export) terminal will get completed and start taking Colorado gas in the near future so that we see an associated uptick in economic growth on the West Slope,” Sgamma said.

Conservation groups challenging BLM leasing “have an uphill battle convincing a judge” because current policy has included opportunities for public comment, she said. “They just don’t like the new policy because it doesn’t drag the lease process on for years, as was the case previously. The bottom line is that administrations have the ability to enact changes in policy as long as they comply with the law.”