Wilhelmsen is a member of the Custer Battlefield Historical and Museum Association and the Little Big Horn Associates, as well as a past director of the Los Angeles Adventurers Club. His chosen career as an adventure film producer and lecturer took him on extensive travels throughout South America, Africa, Mexico and the southwestern United States. He rafted down the Amazon River, was attacked and woulded by bandits while exploring in the mountains of Columbia, is credited with discovering a pre-Inca city in the Andes Mountains of Peru, and Spanish conquistador armor he exhibted at the Southwe...