DENVER (AP) — A federal judge has indefinitely blocked oil and gas drilling on a wildlife refuge that sits next to the Great Sand Dunes National Park in south-central Colorado.

U.S. District Court Judge Walker Miller on Thursday granted a preliminary injunction, ruling environmental groups presented adequate evidence that drilling would cause irreparable injury to Colorado’s Baca National Wildlife Refuge.

Miller’s decision blocks drilling while an environmental lawsuit moves through court.

Toronto-based Lexam Energy Exploration had acquired the mineral rights in 1997 before the former Baca Ranch was bought by the federal government for a wildlife refuge. A message left for Lexam officials was not immediately returned.

Federal law gives mineral-rights holders the right to reasonable use of the surface to extract minerals. Lexam holds the surface rights until 2011, according to court documents.

The San Luis Valley Ecosystem Council and Citizens for San Luis Valley-Water Protection Coalition claims that the government’s conclusion that drilling would have no significant effect is wrong and asked officials to conduct another environmental analysis.

In his ruling, Miller noted that the refuge contains wetlands, habitat for a variety of wildlife and fish, and: a “large expanse of undeveloped land with a significant ‘sense of place’ and quiet.’”

The federal government acquired the 97,000-acre Baca Ranch to preserve the terrain and geological features responsible for the sand dunes. Some of the land became part of the national park, with the rest becoming the refuge in 2004.

The refuge, about 200 miles southwest of Denver, is home to several colonies of Gunnison’s prairie dogs, a candidate species for the endangered list. It’s also used by migratory birds, burrowing owls, songbirds and elk.