Spread across an arid plain that lies between the Pacific coast and the Andean foothills of southern Peru, an enormous tangle of forms, the “Nazca Lines,” poses one of the world’s most tantalizing archaeological mysteries. Here a 200-square-mile expanse of land is embossed with piles of rock and shell arranged in lines that form more than a hundred giant geometric shapes and figures–animals, birds, insects, plants–some of which become coherent only when looked down on from an altitude of at least 1,000 feet.

He discovered the last nomadic hunting and gathering tribe–the Raute–in the Himalayas. The Raute still kill monkeys with clubs and trade wooden bowls for grain. Reinhard came across them while investigating the yeti, the abominable snowman. Some villagers near the Himalayas believe that yetis are manifestations of mountain gods.

He climbed 19,300 feet in Chile to a crater containing the world’s highest lake. Exploring underwater, he discovered a previously unknown ecosystem and a new species of zooplankton. The millions of crustacean larvae astonished Reinhard, as he was beyond the altitude at which fish and vegetation survive. He also found Incan ruins on the crater’s rim.

Reinhard finds it difficult to come home for more than brief periods of time. “It’s always hard to adjust to American culture,” he admits. “I remember one return visit, I wanted a chocolate bar and I walked into this supermarket. There was a whole wall of chocolates, and I turned around and walked out. After not having access to something as simple as a chocolate bar, and then seeing more than you’d ever want, you’re literally frozen. It’s difficult to deal with the overabundance of American society.”

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The job took him to Nebraska, Kansas, Iowa, and southern Illinois, where “it seemed like all the other workers were from the south.

Two years later, Reinhard was visiting a friend whose family had moved to Brazil, and that’s where the anthropology bug bit. “I was hooked. Anthropology combines philosophy, learning about other cultures, exploration, discovery, in short, thinking and doing–all in one profession.” He enrolled at the University of Arizona, then moved on to the University of Vienna, where he received his undergraduate degree and, in 1974, a PhD from the department of anthropology.

Making the ruins doubly remarkable is the altitude at which they were built; in addition to the physical stamina required to attain those heights, the builders needed unusual courage to enter the domain of the mountains’ deities and evil spirits. Reinhard discovered that the Incas knew more about mountain climbing than they’ve been given credit for. They’d solved many of the basic problems of high-mountain ascents. “We tend to take such solutions for granted today,” Reinhard says, “but in mountaineering terms they represented a great step forward. One of these was the use of a base camp, with camps at intervals on up the mountain. There are also buildings on the summits that clearly indicate they were used as temporary refuges, most likely for a single night. Offerings were made during the night or at sunrise.”