U.S. District Judge David Campbell has upheld the U.S. Department of Interior’s 20 year-ban on exploration and development of uranium mining claims on 1 million acres near the Grand Canyon National Park.

The withdrawn land includes a north parcel of 550,000 acres, an east parcel of 135,000 acres, and a south parcel of 322,000 acres. Only the mining of a few existing claims will be permitted.

Plaintiffs in the case included the National Mining Association and the Nuclear Energy Institute, the Arizona-Utah Local Economic Coalition, Quaterra Resources, and an individual, Gregory Yount, with interests in uranium mining. Motions for summary judgment were filed by Plaintiffs American Exploration & Mining Association and Yount.

Defendants included the U.S. government, the Center for Biological Diversity, the Grand Canyon Trust, Havasupai Tribe, National Parks Conservation Association and the Sierra Club.

On January 9, 2012, then-Secretary of the Interior, Ken Salazar, and the U.S. Department of Interior issued a record of decision (ROD), which withdrew 1,006,545 acres from mining pursuant to the Federal Land Policy and Management Act (FLPMA).

The Record of Decision (ROD) justified the withdrawal “on the basis of (1) threats and uncertainty regarding the effect of uranium mining on water resources, (2) impact of uranium mining on cultural and tribal resources, (3) the need for more study of the impact of uranium mining on other resources including wildlife, and (4) the existence of pre-approved mines and valid existing rights in the withdrawn area that will not be affect by the withdrawal,” said the court in a decision issued Tuesday.

In his decision, Judge Campbell noted, “Ultimately the question in this case is whether DOI, when faced with uncertainty due to a lack of definitive information, and a low risk of significant environmental harm, can proceed cautiously by withdrawing land for a period of time under the FLPMA.

“The Court can find no legal principle that prevents DOI from acting in the face of uncertainty. Nor can the Court conclude that the Secretary abused his discretion or acted arbitrarily, capriciously, or in violation of law when he chose to err on the side of caution in protecting a national treasure—Grand Canyon National Park.

“IT IS ORDERED that Defendants’ motions for summary judgment … are granted. Plaintiffs’ motions for summary judgment are denied,” Campbell ruled.

The plaintiffs have 60 days to appeal Judge Campbell’s decision to the Ninth Circuit Court of Appeals.