A mountain climber, Petzoldt climbed before it was popular — and before he knew what he was doing: he made his first (of more than 300) ascent of the 13,772-foot Grand Teton at age 16, wearing blue jeans and cowboy boots.
Realizing he needed to be much better prepared, he developed climbing gear and procedures still in use today. During World War II, Petzoldt trained the U.S. Army’s 10th Mountain Division, teaching them skiing and mountain combat. In 1965, he founded the National Outdoor Leadership School, which has trained more than 50,000 people in outdoor safety and preparedness. Petzoldt died in Maine of cancer on October 6. He was 91.