Gene Gillis, who helped develop Keystone Mountain with founder Max Dercum, died Friday at the age of 80.Gillis was born on April 17,1925 in Bend, Ore., and learned to ski at age three. The sport became his lifelong passion.In 1947, he trained for the winter Olympics and was named to the 1948 U.S. Alpine Olympic Team.He later taught skiing, coached racers and became a well-known ski area developer, notably at Mt. Bachelor in his hometown of Bend, Stratton Mountain in Vermont and at Keystone.Gillis moved to Summit County in 1971, and teamed up with Max Dercum, who had already done a lot of work on the mountain, but invited Gillis to help with the North Peak and Jones Gulch areas, according to the “Summit Pioneers” book. Gillis was also responsible for the installation of snowmaking at Keystone after checking snowfall levels and determining man-made snow would be crucial to the resort’s financial success, then relaying that information to the water board, the book said.He was a co-founder of the Summit Ski and Education Foundation and head coach of the Summit Race Team.He was always willing to help others improve their skiing and share his love of the sport.Later in life, Gillis developed serious hip problems and then was diagnosed with Alzheimer’s Disease.He is survived by his wife Ina.A private family service is scheduled, please do not send flowers or food.A ski day will be held at a later time to celebrate Gillis’ lifelong devotion to the sport. Donations to the Reagan Alzheimer’s Foundation will be accepted at that time.