The great east–west Colorado corridor I–70 cleaves through the heart of Summit County, punching west from Denver past Idaho Springs and Georgetown. The traffic here can be heavy and fast; everyone is in a hurry to make it through the Eisenhower Tunnel, the traditional gateway to Summit County. Those with an extra half hour and a yearning for hairpin turns, shaggy mountain goats, and 100-mile views opt for U.S. 6 over Loveland Pass and the Continental Divide. As it drops into the Summit County Basin on the west side of the divide, U.S. 6 passes Arapahoe Basin and Keystone Ski Resort before merging with I–70. Both roads skirt Dillon Reservoir, with its shoreline communities of Dillon and Frisco. The highway quickly disappears back into a narrow mountain valley and climbs to Copper Mountain and then up and over Vail Pass.
Keystone and Arapahoe Basin. Tucked up a western valley off the Continental Divide, Keystone and Arapahoe Basin tend to attract more of a local—and hardier—ski crowd, and hikers in summer. Keystone is an intimate resort town but "A-Basin" is little more than a ski area.
Lake Dillon and Breckenridge. Dillon and Frisco are twin towns hugging the shores of Dillon Reservoir, a sparkling human-made lake. Skiers will bypass both for Breckenridge, the largest ski area in Summit County. "Breck" has a blend of authentic Colorado character with a flashy dose of upscale lodges and high-end condos.
Copper Mountain and Leadville. Farther west on I–70, Copper Mountain makes up for a lack of mountain charm with its near-perfect ski mountain. The high-altitude mountain town of Leadville will leave you breathless, both from the thin air and from the gorgeous views of Colorado's highest peak, 14,440-foot Mount Elbert.