LaChapelle was born and raised in Tacoma, Washington. Following high school at Stadium High School, he served in the Navy from 1944 to 1946, and then attended the University of Puget Sound, graduating in 1949 with degrees in physics and math. He then studied at the Swiss Federal Institute for Snow and Avalanche Research in Davos, Switzerland from 1950 to 1951, and returned to the US to work as a snow ranger for the Forest Service in Alta, Utah, starting in 1952. Montgomery Atwater, who had established the first avalanche research center in the Western Hemisphere at Alta over the preceding 7 years, said of his new hire: "To describe Ed LaChapelle is to write the specifications for an avalanche researcher: graduate physicist, glaciologist with a year's study at the Avalanche Institute, skilled craftsman in the shop, expert ski mountaineer. He even looked like a scientist, tall and slender with a slight stoop and that remote look in his eye which means peering into one's own mind."[1] LaChapelle worked at Alta for the next two decades, eventually becoming head of the avalanche center.
He married Mary Dolores Greenwell and they had a son Randy (later changed his name to David) whom they homeschooled and offered a life filled with skiing, art, high mountain adventures and a crucial blend of Ed's scientific, mechanically oriented and inventive mind and Dolores' care for the earth and what the field of her work would later call Deep Ecology. They would travel with the seasons following Ed's professional work and so they shared their time between three homes: Alta in the winter, Blue Glacier in the summer and Kirkland the rest of the year.
Ed and Meg were in Colorado to attend the memorial service of his former wife, Dolores LaChapelle, in January 2007. They were doing what Ed liked best, skiing powder snow at Monarch Ski Area near Salida, Colorado, when he suffered a heart attack at the high altitude.