The land is being "segregated" for two years so that the department can study whether it should be permanently withdrawn from mining activity, said the official, who requested anonymity because he wasn't authorized to speak publicly on the matter.
The announcement comes ahead of Tuesday's congressional hearing on a bill to set aside more than 1 million acres of federal lands north and south of the canyon. The bill's sponsor, Democratic U.S. Rep. Raul Grijalva of Arizona, and environmental groups had been looking to Salazar for temporary protections at the Grand Canyon while the legislation is pending.
The Interior Department under President George W. Bush was unresponsive to efforts to ban new uranium mining claims. The House Natural Resources Committee invoked a little-used rule to stop any new claims for up to three years, but Interior officials refused to recognize the action and continued to authorize additional mining claims.
A coalition of environmental groups sued, and the U.S. Bureau of Land Management later rescinded Congress' right to withdraw lands from mining and other activities in emergencies.
Since then, environmentalists and Grijalva have been hanging their hopes on Salazar for temporary protections.
Any companion bill to Grijalva's in the Senate is unlikely to come from Arizona's two U.S. senators. Republicans John McCain and Jon Kyl told Grijalva in a letter last month that adequate protections already exist.
Conservationists contend mining leaves the Grand Canyon vulnerable to environmental damage and that no new operations should be proposed when the old mining sites haven't been cleaned up.
There are as many as 10,000 existing mining claims on BLM and U.S. Forest Service lands near the Grand Canyon for all types of hard-rock exploration. Some 1,100 uranium mining claims are within five miles of the Grand Canyon National Park.
The protections offered by Salazar won't include uranium mining claims already filed near the Grand Canyon, the official said. It's not possible to prevent existing claims under the General Mining Act of 1872 unless Congress was to appropriate money for the department to buy up the claims, he said.
Former Grand Canyon National Park Superintendent Rob Arnberger said he would welcome any protection that Salazar offers, but permanent withdrawal is the goal.
"Are we prepared to allow the landscape to be torn up adjacent to the park, to threaten the hydrological and the natural resources of that park?" Arnberger said. "My answer to that is no. Don't open it up to exploration."
Associated Press Writer Felicia Fonseca reported from Flagstaff, Ariz.