Environmental groups filed two separate lawsuits Monday that claim the Trump administration violated sage grouse protections by opening up more land to oil and gas leases, including in Nevada. The lawsuits allege that the new administration worked “systematically” to unravel 2015 plans to boost populations of the large Western bird found across sagebrush country.

“This case challenges the Trump Administration’s systematic disregard of legally binding land management plans adopted to protect the greater sage-grouse,” wrote lawyers for the Audubon Society, the Wilderness Society, the National Wildlife Federation and the Montana Wildlife Federation.

They said Department of Interior officials violated land management laws when they released a memo that reinterpreted the 2015 rules, which sought to prioritize oil and gas leasing outside of sensitive sage grouse habitat. The lawsuit, filed in Montana, also said thousands of acres of oil and gas leasing, from Nevada to Wyoming, ignored the Obama-era sage grouse plan.

Another lawsuit, filed Monday in Idaho by the Western Watersheds Project and the Center for Biological Diversity, similarly claimed that the administration’s actions disregarded the Obama-era plan without proper notice and analysis. It resulted, the lawsuit alleged, to opening up more land to oil and gas in areas where ground disturbance could impact sage grouse habitat and behaviors. The bird is found in 15 of 17 counties in Nevada. Because the state’s oil industry is small, oil and gas leasing has had minimal impacts on the bird’s population, compared to a state like Colorado.

But the lawsuit warns that might change with a proposed sale next month near Eureka.

“Because of relatively limited oil and gas production and development in the state, habitat loss to oil and gas has thus far been limited,” wrote lawyers who said the bird’s biggest threat in Nevada is often habitat loss because of invasive species and wildfire. “The June 2018 lease sale, however, would convey rights to potentially vast development in what the Nevada Department of Wildlife deems the most productive grouse habitat in southern Nevada.”

In 2015, the Obama administration finalized a series of land management rules to bolster sage grouse populations in 10 Western states. The plan’s goal was to prevent listing the sage grouse as an endangered species, an action that most lawmakers and developers see as damaging to economic development in the rural West. But the compromise plan to defer some development, despite bipartisan support, remained controversial for industry groups.

They have pushed the Trump administration to reverse course on the 2015 plan.

In addition to the actions cited in the lawsuits, the administration started a formal process last year to revise the sage grouse plans. Republican and Democratic governors have cautioned against any wholesale changes to the 2015 plans. Last year, Gov. Brian Sandoval said he wanted to ensure that the state retained control of its sage grouse plans if new rules are approved.

Update: An earlier version of this story referred to the National Wildlife Federation as the "Wildlife Federation." The story was updated at 8:40 a.m. on May 1 to correct the error.