The entire geological history of Colorado is written in the sediment of Glenwood Canyon, a spectacular gorge nearly 30km/18mi. The section of the I-70 that spans the canyon extends cantilevered over the river, fixed to the granite wall and winding through a series of small tunnels. A paved trail for cyclists and runners also spans the canyon from one end to the other, going as far as the Hanging Lake Trail, which rises to 304m/997ft for 1.8km/1.1mi to reach a wonderful lake.