Colorado-based conservation advocates spoke out as the Trump administration finalized plans Thursday to allow mining and drilling on vast swaths of former national monuments in southern Utah, including near the Four Corners.

Much of the acreage was once protected as part of the 1.3-million-acre Bears Ears National Monument set aside in 2016 by President Obama.

In December 2017, President Trump cut the monument’s acreage roughly in half to open it up for resource development. He also reduced Utah’s 1.9 million Grand Staircase-Escalante National Monument, which was established by President Clinton in 1996.

According to the plan finalized by the Interior Department Thursday, 861,974 acres of land of newly unprotected land could host oil, gas and coal operations.

The fight, however, isn’t over, according to the Denver-based the Center for Western Priorities.

“The only certainty today’s announcement creates is of a long drawn-out court fight to stop yet another unprecedented attack on America’s public lands by the Trump administration,”  policy director Jesse Prentice-Dunn said in a statement. “With these plans, the administration is racing to allow new development on formerly protected public lands before the courts can overturn its illegal action.”

Coloradans have been engaged in the fight to preserve the land again, with conservationists hoping to get Trump and fellow Republicans out of power this November.

Colorado Sen. Michael Bennet proposed federal legislation in the Republican-held Senate in 2018 to limit the president’s power to make such a cut.

U.S. Rep. Ken Buck, who is now the state Republican Party leader, backed up President Trump’s decision.

“President Obama designated Bears Ears Monument without congressional approval or the support of the people of Utah,” Buck told Colorado Politics two years ago. “I support President Trump’s reversal of this decision and believe that future national monument designations should only be implemented with the support of the local communities that are impacted.”