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 4540 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.