THE HIGHWAY THAT SHOULDN'T EXIST ENGINEERS HAD NO ROOM LEFT FOR A HIGHWAY Interstate 70 through Glenwood Canyon wasn’t blasted into the rock like most highways. Engineers built miles of elevated viaducts pinned into the canyon walls so the road could float above the Colorado River and railroad below. Colorado outdoors Hidden Colorado Colorado camping Colorado hiking Locals only Colorado Wild Colorado Colorado adventure Glenwood Canyon Colorado Interstate 70 Glenwood Canyon Glenwood Canyon engine