Trail Ridge Road is a 48-mile section of U.S. Highway 34 crossing Rocky Mountain National Park between Estes Park and Grand Lake, and with Beaver Meadow Road it forms a 55-mile National Scenic Byway. Rising to 12,183 feet, it is the highest continuous paved road in North America and traverses high tundra along Trail Ridge after crossing the Continental Divide at Milner Pass. The route follows a corridor long used by Native peoples, including Arapaho and Ute travelers. Built from 1929 to 1938 to replace the steeper, more limited Fall River Road, it expanded automobile access while aiming to minimize harm to the alpine landscape.