Northern Corridor Highway Followup

May 11, 2026 — Advocates for the West and our partners amended our February lawsuit over the Bureau of Land Management (BLM) and U.S. Fish and Wildlife Service’s failure to adequately protect the threatened Mojave desert tortoise when reapproving the Northern Corridor Highway in January 2026. The long-opposed highway would tear through critical habitat for the Endangered Species Act (ESA)-protected tortoise within Red Cliffs National Conservation Area near St. George, Utah.

In addition to other laws, the newly filed complaint alleges new violations of the ESA by the Fish and Wildlife Service and BLM—including for the unlawful disposal of lands purchased using federal funding intended to protect the tortoise to make way for the highway. Fish and Wildlife Service’s final environmental analysis supporting the land disposal was issued on the same day in February 2026 that the conservation groups, represented by Advocates for the West, filed the lawsuit challenging the illegal highway’s reapproval. The amended complaint was filed now to comply with the required 60-day notice to federal agencies of ESA violations.

March 1, 2026 — The U.S. District Court granted a motion by Advocates for the West and our partners to block ground-disturbing activities associated with construction of the Northern Corridor Highway through the Red Cliffs National Conservation Area near St. George, Utah. The Court’s injunction prohibits the Utah Department of Transportation (UDOT) from starting construction-related activities that would cause irreparable harm to the threatened Mojave desert tortoise. UDOT insisted on moving forward with these activities as quickly as possible despite uncertainty about its final highway plans and conservation organizations’ pending lawsuit that seeks to again declare the highway illegal. In granting the injunction, the judge found that conservation organizations’ lawsuit is likely to succeed in showing the highway approval is unlawful.

February 18, 2026 — Advocates for the West filed our reply brief in support of our motion for preliminary injunction.

February 10, 2026 — Advocates for the West filed a motion for preliminary injunction and supporting brief to prevent further ground disturbance associated with construction of the Northern Corridor Highway right-of-way.

The Bureau of Land Management authorized immediate ground-disturbing activities through interim notices to proceed following the agency’s January 21, 2026 approval for the highway. These activities will result in harm to the threatened Mojave desert tortoise as well as damage to protected resources and conservation values of the Red Cliffs National Conservation Area.

February 4, 2026 — Advocates for the West and a coalition of six local, Utah-based, and national conservation organizations sued the Bureau of Land Management (BLM) and U.S. Fish and Wildlife Service for illegally reapproving the four-lane Northern Corridor Highway through the Red Cliffs National Conservation Area near St. George, Utah. Conservation groups filed the lawsuit after receiving information that the Utah Department of Transportation (UDOT) would be starting ground-disturbing activities for the highway’s construction based on interim authorizations from BLM and despite BLM having yet to approve a required highway development plan for public lands managed by the agency.

The proposed Northern Corridor Highway would carve a high-speed highway through designated critical habitat for the threatened Mojave desert tortoise within Red Cliffs National Conservation Area. It would damage iconic redrock landscapes, disrupt treasured outdoor recreation opportunities, and set a dangerous precedent for congressionally protected public lands across the U.S.

Today’s lawsuit, filed by Advocates for the West in the U.S. District Court for the District of Columbia, challenges federal agencies’ January 2026 reapproval of UDOT’s highway proposal for violating multiple federal laws, including the Omnibus Public Land Management Act, Land and Water Conservation Fund Act, Endangered Species Act, and National Environmental Policy Act.

Abandoning their previous scientific findings, the federal agencies’ recent decision reversed a December 2024 rejection of the same proposal by the BLM and Fish and Wildlife Service and marks the eighth time the controversial highway has been considered. The project has been stopped on seven previous attempts over concerns related to wildlife, public safety, legal compliance, and community opposition.

In a decades-long fight, local residents, conservation organizations, and outdoor recreationists have strongly opposed the Northern Corridor Highway. Despite the immense local opposition, the BLM and Fish and Wildlife Service approved a right-of-way for the Northern Corridor Highway in the final days of the first Trump administration. Conservation groups sued, arguing that the approval violated multiple federal laws.

The case resulted in a settlement agreement in 2023, which the BLM’s recent reapproval violates, and a U.S. District Court decision sending back the project’s 2021 right-of-way approval for reconsideration. Agencies acknowledged that the approval did not comply with the National Historic Preservation Act and required additional environmental analysis in light of recent wildfires that further degraded Mojave desert tortoise habitat and native vegetation. After updating its environmental analysis, the BLM again rejected the project in late 2024.

The agency’s 2024 Supplemental Environmental Impact Statement found the project would increase wildfire probability and frequency, permanently eliminate designated critical tortoise habitat, spread noxious weeds and invasive plants, and harm more cultural and historical resources than any alternative considered.

In October 2025, the BLM said it would reconsider the application after UDOT argued that the federally endorsed alternative was economically infeasible, despite documented environmental and community costs associated with the Northern Corridor.