sentences:  The Federal Highway Administration has claimed the section of I-70 through Glenwood Canyon, Colorado, completed in 1992, was the last piece of the Interstate Highway system, as originally planned, to open to traffic.The construction of I-70 in Colorado and Utah is considered an engineering marvel, as the route passes through the Eisenhower Tunnel, Glenwood Canyon, and the San Rafael Swell.The Eisenhower Tunnel is the highest point along the Interstate Highway system, with an elevation of .