easternmost section of the Southern Rocky Mountains, extending about 300 miles (500 km) south-southeastward from near Casper in southeastern Wyoming to Fremont county in south-central Colorado, U.S. The Front Range is 40 to 50 miles (65 to 80 km) wide and includes Laramie (Laramie Mountains) and Medicine Bow (Medicine Bow Mountains) mountains; the Sangre de Cristo Mountains are usually regarded as an extension. Many summits exceed 13,000 feet (4,000 metres), including Mount Evans (14,264 feet 【4,348 metres】), which is the range's highest peak, and Pikes Peak (14,110 feet 【4,301 metres】). Notable passes are Berthoud (11,315 feet 【3,449 metres】) and Loveland (11,990 feet 【3,655 metres】). The mountains are composed largely of gneiss, schist, and granite.

Lying largely within conservation areas, the Front Range constitutes the whole of Rocky Mountain National Park and occupies portions of Pike, Arapaho, Routt, Roosevelt, and Medicine Bow national forests. The range is known for its variety of minerals and its recreational appeal, and it serves as a source region for headstreams of the Cache la Poudre and Colorado (Colorado River) rivers.