Court action filed to protect resources, public involvement in massive Wyoming drilling project

Advocates for the West and our conservation partners are challenging an attempt by the Bureau of Land Management (BLM) to sidestep a 2024 court order halting the Converse County Oil & Gas Project in the southern Powder River Basin of Wyoming and unlawfully expedite development of new wells. Powder River Basin Resource Council and Western Watersheds Project, represented by attorneys from Advocates for the West, filed a supplemental complaint in our lawsuit challenging the massive 5,000-well project.

“Oil and gas drilling in this area has already had major impacts on air and water quality for local communities and has further threatened sensitive wildlife like sage-grouse,” said Sarah Stellberg, Staff Attorney at Advocates for the West, who is representing the conservation groups. “By plowing ahead with the project despite an unresolved court order halting new drilling permits, the BLM is rubbing salt in the wounds of the communities and species negatively impacted by this behemoth industrial development.”

“BLM has the opportunity to require stronger mitigation to reduce the harmful impacts from oil and gas drilling to communities and ecosystems,” said Hannah Goldblatt, Staff Attorney at Advocates for the West. “Instead, it is doubling down on a minimal environmental review process with no public input.”

“This action is crucial to ensure that our community’s precious groundwater is protected. The first challenged oil and gas project was paused due to a dangerously inaccurate groundwater analysis,” said Donna Birkholz, Powder River Basin Resource Council Executive Director. “The federal government’s actions to now sidestep public process and cut corners in environmental analyses does a disservice to the community members who rely on this water for their livelihoods and health.”

“The federal government is supposed to be in a shutdown, yet the Trump administration has been quietly approving hundreds of drilling permits—for a project already halted by court order—without any opportunity for public input,” said Erik Molvar, a wildlife biologist and Executive Director with Western Watersheds Project. “This drilling will fragment sage-grouse habitats, disturb nesting birds of prey, and generally industrialize the grassland ecosystems of eastern Wyoming. It’s a sneak attack by Big Oil, involving federally-owned minerals that are supposed to be managed for the public’s interests, advanced by this administration.”

At Issue

Despite the Court’s September 2024 ruling blocking approval of additional drilling permits that relied on flawed groundwater modeling, this August, BLM again began approving drilling permits in the Converse County Project area. BLM approved these permits with minimal environmental review and no public process. It also continued to rely on a flawed groundwater analysis, and repeated other legal errors at issue in conservation groups’ initial lawsuit.

The Delaware-sized project, approved under the first Trump administration, is projected to have a major impact on air quality locally and regionally. The massive industrial project will also create irreversible negative impacts to wildlife through special exemptions from traditional habitat protection measures. Overall, the project threatens the survival of sage-grouse and birds of prey throughout the project area.

A key claim in the lawsuit challenges the Bureau of Land Management’s refusal to regulate “Fee/Fee/Fed” wells in the project area, which are wells that drill directionally into federal minerals from adjacent non-federal lands. This illegal BLM practice allows fossil fuel companies to extract publicly-owned minerals without common-sense environmental protections. The Converse County Project consists predominantly of Fee/Fee/Fed wells.

In addition to groundwater and wildlife impacts, BLM’s own analysis projected that the Converse County Project will drive regional air quality to unhealthy levels and impair visibility in National Parks in surrounding states. However, the agency unlawfully claims that it does not have authority to require air quality mitigation measures.

Background

In September 2024, a federal district court ruled that the BLM’s approval of the Converse County Oil & Gas Project was illegal because the agency’s groundwater modeling contained a major error and grossly underestimated the depletion of groundwater by the massive oil and gas project. In June 2025, the BLM issued a new groundwater analysis purporting to fix the error found by the court, but doubling down on other flawed assumptions that underestimated the project’s groundwater usage.

Now, BLM is trying to sidestep federal environmental laws by unlawfully segmenting its environmental review obligations into piecemeal, bare-bones analyses. This means that its new drilling permit approvals fail to take any meaningful look at the cumulative effect of oil and gas drilling in this area, despite the interrelated nature of the activities and their environmental effects on wildlife, air quality, groundwater, the viewshed, and the community.

In September 2022, Advocates for the West launched the initial legal challenge representing Western Watersheds Project and Powder River Basin Resource Council. The lands affected are the traditional homeland of the Lakota (Sioux), Tsis tsis’tas (Cheyenne), and Apsàalooke (Crow) peoples.