Andrew J. Kauffman II, 82, a retired Foreign Service officer and enthusiastic mountain climber who was widely known in the mountaineering community for participating in the first ascent of "Hidden Peak" in the Karakoram region of Pakistan, died Dec. 24 at Villa Rosa Nursing Home in Mitchellville. He had Parkinson's disease.

From 1943 until 1966, Mr. Kauffman was a Foreign Service officer specializing in the analysis of political and military affairs. His posts included Ankara, Turkey; Paris; Calcutta; and Tegucigalpa, Honduras. He worked on U.S.-Soviet relations in the final years of his career, based in Washington.

But his passion was mountain climbing, and in 1958 -- with Peter K. Schoening of Seattle -- he reached the summit of the previously unclimbed Gasherbrum I, also is known as Hidden Peak. At 26,470 feet, it is one of the 10 highest mountains in the world, and it is the only mountain of more than 8,000 meters where the first ascent was made by a U.S. team.

"In the climbing world, a first ascent is about the most significant thing you can do," said Lloyd Athearn, deputy director of the Colorado-based American Alpine Club. Mr. Kauffman, he said, was "certainly among the leading American climbers of his generation."

In the 1940s and 1950s, Mr. Kauffman climbed extensively in the Canadian Rockies and the Andes in South America, participating in expeditions that achieved several first ascents. To mountaineers, he was known as a man of unusual strength and stamina who was loath to quit under the most adverse conditions.

"He is like the Energizer Bunny -- he goes on forever," a friend and climbing colleague, William L. Putnam, told The Washington Post's John M. Berry in 1999. "He could carry very heavy loads. Sometimes we would have to pick them up and put them on his back, but then he could just keep on going."

With Putnam, Mr. Kauffman was author of two books. "The Guiding Spirit" was about the life of Edward Feuz Jr., one of the Swiss guides brought to the Canadian Rockies by the Canadian Pacific Railway in the early part of the 20th century. "K2 -- The 1939 Tragedy" concerned the mystery surrounding the deaths of four men who unsuccessfully attempted to reach the summit of the as-of-then unclimbed K2, the world's second-highest mountain. He was editor of "Mountaineering for Beginners," published in 1978.

Mr. Kauffman, a longtime resident of Washington, was born in Philadelphia and grew up in Geneva, where he became fluent in French. His father was the League of Nations correspondent for the New York Herald Tribune. During the Depression, Mr. Kauffman lived in Washington, where his father was an editorial writer for The Washington Post.

He graduated from Harvard University, where as president of the Harvard Mountaineering Club he did some early climbing on the icy slopes and ravines of Mount Washington in New Hampshire. Years later, it would become a legend of his backpacking endurance and stamina that while at Harvard, Mr. Kauffman climbed five flights of stairs with a 400-pound box of climbing gear strapped to his back, simply as a training exercise.

He tried to join an Army mountain unit during World War II. But an obscure heart murmur rendered him unfit for military service, although it would not interfere with subsequent decades of climbing up the sides of steep mountains at high altitudes in miserable weather.

Mr. Kauffman then joined the State Department. His career included monitoring a State Department hotline to Moscow during the peak years of the Cold War with the Soviet Union and keeping tabs on French politics. In this capacity, he wrote a detailed and, it turned out, prescient memorandum on the consequences of Charles de Gaulle's return to politics.

Mr. Kauffman was posted in Paris early in 1958 when he was invited to participate in the Hidden Peak climbing expedition, and he applied for a leave of absence. Told informally in Paris that his request had been approved, he left for Pakistan. Once there, and having reached the summit of Hidden Peak, he found out the request had been denied by officials in Washington. By then, his supervisors at the State Department decided that since he was already in that part of the world, they would assign him to an opening in the U.S. consul's office in Calcutta. He spent the next three years there.

Both literally and figuratively, the ascent of Hidden Peak was the summit of Mr. Kauffman's climbing career. In the 1960s and 1970s, he led backpacking trips into some of the less-strenuous terrains of the Canadian Rockies, and he did rock climbing in the area. To novice and younger climbers, he was sometimes known as "Uncle Andy."

He was a director and vice president of the American Alpine Club and an honorary member of the Himalayan Club of India and the Groupe de Haute Montagne, an exclusive organization of French mountaineers.

Mr. Kauffman's marriage to Betty Conant ended in divorce. He was separated from his second wife, Daphne Ennis Kauffman.

He leaves no immediate survivors.