Immigrating from Switzerland, their father Louis and mother Marie eventually settled in Colorado Springs, raising a family by the nearby mountain Pike's Peak. Louis was especially skilled in exploring the then new-fangled automobile engine which sparked the interest of the sons. On September 1915 they rode a motorcycle and sidecar to the summit of Pike's Peak, a mountain previously declared to be unscalable. Soon after  this conquest, the Colorado City police hired the three Unser brothers to teach them how to ride motorcycles, and in 1916 after a road was built, Spencer Penrose officially staged a "Race to the Clouds", a 12.4 mile race to the peak. The Unser boys were regular competitors.