President Barack Obama is expected to announce that nearly 500,000 acres in New Mexico will be a national monument, creating the largest of his administration. It will make the land off-limits for developers, protecting the area’s beauty for future generations.

Obama is expected to announce that the Organ Mountains-Desert Peaks region will become a national monument on Wednesday, reports The Washington Post. The region, which contains desert grasslands, a petrified forest and petroglyphs from Native Americans, is twice as large as Obama’s previous biggest national monument, New Mexico’s Rio Grande del Norte National Monument.

The land is currently owned by the federal Bureau of Land Management, notes the Albuquerque Journal. The 496,000 acres are near Las Cruces, which will welcome U.S. Interior Secretary Sally Jewell on Friday to celebrate the new national monument.

As for Wednesday's announcement, it will be held at the Department of the Interior, where Obama will sign the official document. “By establishing the monument, the president will permanently protect nearly 500,000 acres to preserve the prehistoric, historic and scientific values of the area for the benefit of all Americans,” the White House said Monday.

However, Rep. Steve Pearce, (R-N.M.) and Rep. Rob Bishop (R-Utah) were not happy about Obama’s decision to bypass Congress to designate the area a national monument. They believe that the designation doesn’t give the area enough protections for the U.S. Customs and Border Protection. Specifically, Pearce was hoping to get legislation passed that would protect 58,000 acres in the Organ Mountains.

“It bypasses the will of the people. It’s not going to be good for the county and it will depress the economy over the long term and make it harder for the rural, New Mexico way of life to continue,” Pearce told the Journal.

Sen. Martin Heinrich (D-N.M.) was pleased, though, saying ti reflected advocates’ hard work. “Anytime you have a recognition of that work that reaches all the way to the White House, that’s pretty special,” he told the Post.