"If skiers or riders get a sudden urge for french fries when they see a grooming vehicle on the slopes, now they'll know why," said GM David Crowley. Wachusett Bio-Mass in Princeton takes all of the area's 2,500 gallons of waste cooking oil and converts it into fuel to run five snowcats and four diesel-powered backup generators for the chairlifts. The process allows the mountain to burn up to 20 percent less diesel fuel and helps reduce harmful emissions by up to 50 percent per gallon of biodiesel fuel burned. Sugarloaf/USA in Maine, Okemo in Vermont, and Sunapee in New Hampshire also use biodiesel in their vehicle fleets.