Mr. Dennison, who lives in Rancho Cordova, a town about 15 miles east of Sacramento, could not be reached for comment. His telephone has been disconnected, and several friends and former colleagues said they did not know his whereabouts. In an interview in today's Sacramento Bee, Mr. Dennison said the bomb could only be the work of "a sick person."

"I can't imagine that what we do could be a threat to give the least reason to bomb an office," Mr. Dennison told The Bee, which first identified him as the intended target. He added: "If trying to manage natural resources is a threat, I don't know what isn't. There can't be any rationale for this." The newspaper did not indicate the circumstances of the interview or from where Mr. Dennison spoke.

Jean Wilhoit, the public affairs director for the P.&M. Cedar Products Company in Stockton, Calif., and a board member of the forestry association, said: "I know Bill is completely devastated by what has happened. He has probably cloistered himself until he can collect his thoughts and emotions."

In the years leading up to his retirement, Mr. Dennison was a prominent voice in what was widely known in the Pacific Northwest as "the timber wars," a struggle that pitted ranchers, loggers and the timber industry against environmentalists over the development of public and private lands.

"Bill Dennison was there during a time of fairly contentious issues in California," said Jay Watson, regional director of The Wilderness Society, adding that he was an especially vocal opponent of the Government's 1990 decision to declare the northern spotted owl, which makes its home in the old forests of the Northwest, a threatened species.