WASHINGTON  The Department of the Interior has frozen oil and gas development on 60 of 77 contested drilling sites in Utah, saying the process of leasing the land was rushed and badly flawed.

The 77 government-owned parcels, covering some 100,000 acres in eastern and southern Utah, were leased in the last weeks of the Bush administration. But the leases were immediately challenged by conservation groups, and in January a federal judge blocked drilling on the ground that the Interior Department had failed to follow its own procedures for reviewing the appropriateness of lands designated for oil and gas extraction.

An Interior Department review team then presented Secretary Ken Salazar with a recommendation that drilling be allowed to proceed on 17 of the 77 parcels. But it also said that the leases on eight parcels should be withdrawn and that 52 should be subjected to further study because of potential threats to wildlife and air and water quality.

In announcing Thursday that he had accepted those recommendations, Mr. Salazar said there was a “headlong rush” at the end of the Bush administration to lease the sites, without proper attention to environmental and aesthetic concerns. Some of the parcels are near Arches National Park, Canyonlands National Park and Dinosaur National Monument.