By 1935, when he graduated from UCLA with a degree in astronomy, he had been hiking the local mountains with high school and college friends for a decade. His first contact with the Sierra Club came on one of these early trips when he joined a party going to Mt. Baldy to lay the cornerstone of Harwood Lodge. Finding the market for astronomers nonexistent during the depths of the Depression, Walt joined the Glendale Police Department, where he worked until retirement, reaching the rank of lieutenant.. While chasing criminals, he continued chasing up and down mountains, often joining other Sierrans in pursuit of the elusive Hundred Peaks goal, that is, to climb one hundred peaks on a list of mountains first published and put forth as an idea by Weldon Heald in 1946.
Walt was a member and supporter of dozens of historical organizations, the most prominent of which were The Westerners, Death Valley Fortyniners, E Clampus Vitus, Historical Society of Southern California, and Zamorano Club. But he never forgot his roots in the Sierra Club, expending a portion of his considerable energies in his latter years to encouraging the Backroads Explorers Section.
Wheelock’s greatest literary endeavor was his creation of La Siesta Press, and the subsequent encouragement of many young writers who were published under its imprint. It was Wheelock who published the earliest works of John Robinson, the eminent Southern California mountain historian. The small booklets issued by the Press usually involved climbing subjects or field explorations in Southern California and northern Baja California, some of which were written by Wheelock himself.