Mr. Turnage began his conservation work when the president was Jimmy Carter, whose friendly environmental policy was illustrated by the enactment in 1980 of the so-called Alaska Lands Act. The legislation, spearheaded by Mr. Carter’s interior secretary, Cecil D. Andrus, designated more than 100 million acres for national parks, wildlife refuge and wilderness.
“Seward bought Alaska and Andrus saved it,” Mr. Turnage said, referring to William H. Seward, the secretary of state who negotiated the purchase of Alaska in 1867. (Mr. Andrus died in August.)
But Mr. Turnage had no amicable feelings for James G. Watt, Reagan’s interior secretary, whose stated goal was to transfer significant amounts of federal land to private timber, energy and mineral interests for development.
Mr. Turnage became a frequent and barbed critic. In July 1981 the Wilderness Society published “The Watt Book,” a loose-leaf compendium of actions taken by Mr. Watt that the organization deemed dangerous to the environment — among them imposing a moratorium on acquiring new national parkland and failing to protect national parks from increasing pollution.
“It is both incredible and tragic,” Mr. Turnage said in introducing the book at a news conference, “that a cabinet officer can go astray so quickly that he prompts production of a four-pound book on his actions during his first six months.” He called on Reagan to fire Mr. Watt.
But Mr. Watt was not dismissed and continued to pursue what he described as a “market-oriented, people-oriented” policy to sell public lands and raise money to reduce the federal debt.
When 307 parcels of federal land were about to be sold to private interests in 1982, Mr. Turnage said, “The Reagan administration is pirating the public treasure for public benefit.”
And as energy companies intensified pressure on the administration to approve applications for oil and gas drilling in wilderness areas, Mr. Turnage issued a warning: “If Watt messes with the wilderness system, he will find it is like sticking his hand in a Cuisinart.”
Mr. Watt resigned the next year, having accomplished some but not all of his goals. But his successor, William P. Clark, Reagan’s former national security adviser, did not find a friend in Mr. Turnage, either.
“It’s an appalling appointment,” Mr. Turnage said. “Clark knows nothing about the environment.”
Credit Diane H. Walker/The Wilderness Society
James Morton Turner, author of “The Promise of Wilderness: American Environmental Politics Since 1964” (2012), said in an interview that Mr. Turnage had been a “transformative figure” who developed the Wilderness Society’s abilities to make scientific and economic analyses of public land issues.
“Documenting James Watt’s attacks on public lands was a central part of his legacy,” Mr. Turner said.
William Albert Turnage was born in Tucson on Dec. 9, 1942. His father, William V. Turnage, was an economist for the federal government. His mother, the former Erna Rassow, who was born in Panama, was a homemaker.
After graduating from Yale with a degree in history and studying history at Balliol College, Oxford, Mr. Turnage worked at the Alliance for Progress, an economic assistance program for Latin American countries established by President John F. Kennedy.
He attended Yale Law School but transferred to the Yale School of Forestry and Environmental Studies, while also working as an associate fellow at the Yale Chubb Fellowship. He met Mr. Adams, whose black-and-white pictures of Western American landscapes made him one of the world’s most famous photographers, when Mr. Adams was invited to be a fellow. Mr. Turnage left the school soon after to accept Mr. Adams’s offer to become his business manager.
While they were working together, Mr. Turnage persuaded Mr. Adams, then in his 70s, to stop making prints in his darkroom. “I said, ‘You could continue to concentrate on books,’ ” Mr. Turnage told The New York Times in 2013. “ ‘They’ve been very successful. Your needs aren’t huge. You don’t need to make $3 million a year. You’ll free yourself from the darkroom.’ ”
Mr. Adams agreed — and his photographs became even more ubiquitous, not only in books but also on posters and in calendars.
During his time at the Wilderness Society, Mr. Turnage helped arrange a meeting in 1983 between Reagan and Mr. Adams, who had described Reagan’s environmental polices as “disastrous.” After the meeting, which lasted nearly an hour, Mr. Adams told The Washington Post, “I got a feeling he doesn’t have any fundamental interest or knowledge in the environment as a concept.”
Mr. Turnage left the Wilderness Society in 1985 and took a sabbatical in Europe. While in Kitzbuhel, Austria, he went to a store to buy hiking boots and met Annemarie Murauer, the manager. She eventually became his third wife. (He had by then been twice divorced.)
Mr. Turnage returned to the United States to work at the publishing rights trust established by Mr. Adams, who had died in 1984.
In 2010, Mr. Turnage and the trust became embroiled in a legal dispute over a claim that a box of negatives bought at a garage sale in Fresno, Calif., by Rick Norsigian, who worked in a school maintenance department, were the work of Mr. Adams, from the 1920s and ’30s.
The trust sued Mr. Norsigian, saying that the sale of prints from the negatives was a trademark violation; Mr. Norsigian countersued, claiming that Mr. Turnage, the managing trustee, had slandered him on CNN by saying that attempts to authenticate the negatives as Mr. Adams’s were the work of a “bunch of crooks.”
The dispute was settled in early 2011 with an agreement by Mr. Norsigian not to sell prints and posters using Mr. Adams’s name or likeness. Mr. Turnage continued to work at the trust until last year.
In addition to his brother Robert, he is survived by his wife; his sisters, Margaret Hebson and Diane Keedy; and another brother, James. His earlier marriages were to Andrea Stillman and Charlotte Wilson.
Although Mr. Turnage was not born to environmentalism — his brother Robert said the family was not “super outdoorsy” — he became a strong advocate at the Wilderness Society.
“Bill helped us transition to being the leading voice in protecting and conserving the wilderness, one of those amazing elements of our national heritage,” Mr. Barron, the author, said. “He knew how precious and fragile those places are.”