Mary Sexton is director of the Department of Natural Resources and Conservation. She says the buffer would allow drilling while answering environmentalists' concerns about potential damage to nearby trout fisheries. But Sexton says the restrictions will have little practical effect unless private landowners and the Bureau of Land Management adopt similar measures.

Two environmental groups had asked the state to defer the Sept. 9 sale of the five leases along with 19 more. They said Tuesday that Sexton's buffer plan was inadequate because it did not include enough waterways.