The U.S. Department of Transportation (USDOT) lists the construction of I-70 among the engineering marvels undertaken in the Interstate Highway system, and cites four major accomplishments: the section through the Dakota Hogback, Eisenhower Tunnel, Vail Pass and Glenwood Canyon. The Eisenhower Tunnel, with a maximum elevation of and length of , is the longest mountain tunnel and highest point along the Interstate Highway System. The portion through Glenwood Canyon was completed on October 14, 1992. This was one of the final pieces of the Interstate Highway System to open to traffic, and is one of the most expensive rural highways per mile built in the United States. The Colorado Department of Transportation (CDOT) earned the 1993 Outstanding Civil Engineering Achievement Award from the American Society of Civil Engineers for the completion of I-70 through the canyon.