Bosworth, a career forester who became the agency's 15th chief in April 2001, will step down within a few weeks, Forest Service spokesman Jim Brownlee said Friday. His replacement was being named later Friday.

After growing up in California, Bosworth joined the agency as a forester in 1966 and climbed the ranks through a series of jobs in Washington state, Utah and Montana.

As chief, he was a key player in President Bush's program to increase timber sales and auction off oil and gas leases in roadless areas of national forests. The Clinton adminstration had put that land off-limits to commercial development.

Among the most controversial decisions has been the Bush administration's promotion of logging in Alaska's Tongass National Forest, the nation's largest. Some of the areas the Clinton administration had tried to protect have trails and roads, but many are considered pristine havens for wildlife and waterways or are prized for their scenery and recreation.

"It's my belief that most users want to do the right thing," Bosworth said in 2005 about his agency's plans to encourage off-road enthusiasts to use the forests in an environmentally friendly way.

In October, a government study blamed the administration, not lawsuits by environmentalists, for adding to the costs of logging to salvage timber from an Oregon wildfire. The administration and Republican allies had contended that lawsuits filed by environmentalists led to the increased costs.

Bosworth spent nine years in Utah during two different stints. He served as forest supervisor for the Wasatch-Cache National Forest from 1986-90. Four years later he was back, this time to serve regional forester for the Intermountain Region from 1994-97.