The historic Town of Breckenridge is the Home Rule Municipality that is the county seat and the most populous municipality of Summit County, Colorado, United States. The town population was 4,540 at the 2010 United States Census. The town also has many part-time residents, as many people have vacation homes in the area. The town is located at the base of the Tenmile Range. Summer in Breckenridge attracts outdoor enthusiasts with hiking trails, wildflowers, fly-fishing in the Blue River, mountain biking, nearby Lake Dillon for boating, white water rafting, alpine slides, and several shops up and down Main Street. Every year, Breckenridge hosts the Breckenridge Festival of Film, established in 1981, Ullr Fest every January, as well as an annual Fourth of July parade. The town of Breckenridge was formally created in November 1859 by General George E. Spencer. Spencer chose the name "Breckinridge" after John C. Breckinridge of Kentucky, 14th Vice President of the United States, in the hopes of flattering the government and gaining a post office. Spencer succeeded in his plan and a post office was built in Breckinridge; it was the first post office between the Continental Divide and Salt Lake City, Utah.