The Guanella Pass Scenic Byway is a National Forest Scenic Byway and Colorado Scenic and Historic Byway located in Clear Creek and Park counties, Colorado, USA. The byway traverses Guanella Pass at elevation in Arapaho and Pike national forests. The pass lies above timberline surrounded by Grays Peak at elevation , Torreys Peak , Mount Blue Sky , and Mount Bierstadt . The byway passes through the GeorgetownâÂÂSilver Plume Historic District, and provides access to the Georgetown Loop Historic Mining & Railroad Park and the Georgetown Loop Railroad. The byway is renowned for its spectacular autumn colors during aspen color change from September 10 through October 10 each year.