About Summit County

Summit County is located among the high peaks of the Colorado Rockies, immediately west of the Continental Divide. Our elevation ranges from a low of 7,947 feet above sea level at Green Mountain Reservoir to a 14,270 feet at Gray’s Peak.

Our dry, high-alpine climate yields long, snowy winters that have attracted world-class ski resorts. We have pleasantly warm summers that are ideal for hiking, biking, fishing, backpacking, kayaking and other forms of recreation.

Summit County is centrally located in Colorado, only an hour’s drive from the Denver metropolitan area via Interstate 70, the state’s main east-west transportation corridor.

Towns, Resorts & Federal Lands

Included within the county are six municipalities (Blue River, Breckenridge, Dillon, Frisco, Montezuma, and Silverthorne), four major ski areas (Arapahoe Basin, Breckenridge, Copper Mountain, and Keystone), portions of the White River National Forest, some Bureau of Land Management lands, and two Congressionally designated wilderness areas (Eagles Nest and Ptarmigan Peak). About 80% of the land in the county is federal public land.

Natural Features

Several striking mountain ranges converge in the county, including portions of the Gore Range, the Tenmile Range, and the Front Range.

Among Summit’s impressive features is the Blue River, generating three times the flow of any other tributary in the Colorado River Basin. The Blue River and its primary tributaries, the Snake River and Tenmile Creek, define the county’s contours, cutting deep valleys into the mountainous terrain.

In the early 1960s, the Denver Water Board dammed the Blue River to create the 2,790-acre Dillon Reservoir, now a popular site for summer recreation. Green Mountain Reservoir, just north of Silverthorne, uses the Blue River to generate power and provide irrigation to nearby ranchlands.