Colorado has 63 counties and 6 congressional districts: 58 of these counties are wholly within a given congressional district; 5 counties are divided among more than one congressional district.
UNDIVIDED COUNTIES (those wholly within one Congressional District):
- CD # 1: Denver (which is coterminous with the City of Denver)
- CD # 2: Boulder, Clear Creek and Gilpin
- CD # 3: Alamosa, Archuleta, Chaffee, Conejos, Costilla, Custer, Delta, Dolores, Eagle, Garfield, Grand, Gunnison, Hinsdale, Huerfano, Jackson, Lake, La Plata, Mesa, Mineral, Moffat, Montezuma, Montrose, Ouray, Park, Pitkin, Pueblo, Rio Blanco, Rio Grande, Routt, Saguache, San Juan, San Miguel and Summit.
- CD # 4: Baca, Bent, Cheyenne, Crowley, Elbert, Kiowa, Kit Carson, Larimer, Las Animas, Lincoln, Logan, Morgan, Otero, Phillips, Prowers, Sedgwick, Washington, Weld and Yuma.
- CD # 5: El Paso and Teller.
DIVIDED COUNTIES (those split between one or more Congressional Districts):
- Adams: CDs 1, 2 and 4
- Arapahoe: CDs 1, 4, 5 and 6
- Douglas: CDs 3 and 5
- Fremont: CDs 3 and 5
- Jefferson: CDs 1, 2, 3 and 6