Experience the Summer. As you head to Summit County and the mountains in the west, small towns lie scattered in canyons and rivers that provide relaxation all their own. Three towns in Summit County are all within reasonable driving distance of Denver. Lake Dillon, also called the Dillon Reservoir, is a popular destination 10 miles West of the Continental Divide in Summit County. The Small community of Frisco features a quaint main street with street fairs and parades. The town of Breckenridge is more upscale than the previous two cities and features downhill skiing along with a wealth of hotels and lodges.