Understanding Colorado Regions

Colorado is one of the most geographically diverse places in the country. It is eighth in size among the 50 states, with an area of over 104,000 square miles. Elevation varies from 3,315 feet above sea level along the Arikaree River near Wray to 14,433 feet at the peak of Mount Elbert, the highest peak in the Rocky Mountains of North America. The average altitude is about 6,800 feet making Colorado the highest state in the contiguous United States.

Colorado is often divided into several physical regions such as "Western Slope", "Front Range", and "Eastern Plains". Geographical lingo like this is frequently used during weathercasts on 9NEWS.

Below are the definitions of Colorado’s geographical regions and features. Please note that the maps are not to scale.

Denver Metro Area | Foothills | Palmer Divide | Urban Corridor | Eastern Plains | Front Range | Mountains | Western Slope | Continental Divide

Denver Metro Area
Denver-MetroThe Denver metropolitan area consists of eight counties including all of Denver and Broomfield Counties and parts of Adams, Arapahoe, Boulder, Douglas, Elbert, and Jefferson Counties. The metro area stretches over 4,500 square miles from Golden to the west to Watkins to the east. The northernmost city is Longmont and the southernmost location is Castle Rock.
Foothills
Colorado-FoothillsGenerally the foothills are considered the higher terrain between 6,000 and 9,000 feet west of Denver that parallel the Front Range Mountains. The foothills stretch from Roxborough State Park north to the west side of Fort Collins. Evergreen, Morrison, Genesee, Nederland, and Red Feather Lakes are all examples of foothill locations. 
Palmer Divide
Palmer-DivideThe Palmer Divide is a ridge of higher terrain that extends from the Front Range of the Rockies in central Colorado, eastward toward the city of Limon on the Eastern Plains. It separates the Arkansas and Missouri River basins. Cities along the Palmer Divide include Monument, Castle Rock, Parker, Kiowa, and Elbert. It is named after William Jackson Palmer who founded Colorado Springs in 1871.
Urban Corridor
Urban-CorridorThe Front Range urban corridor is the area immediately east and west of Interstate 25 from Cheyenne, Wyoming to Pueblo. More than 85 percent of Colorado’s population lives along the urban corridor within the Fort Collins, Greeley, Boulder, Denver, Colorado Springs, and Pueblo metropolitan areas.
Eastern Plains
Eastern-PlainsThe Eastern Plains (or just “Plains”) is considered all areas of Colorado east of Interstate 25. Sterling, Limon, Burlington, Lamar, La Junta, and Springfield are examples of Eastern Plains locations. 
Front Range
Front-RangeSpecifically the Front Range in Colorado is the eastern most mountain range of the Rocky Mountains stretching from Pikes Peak to the Colorado/Wyoming state line. However, the term “Front Range” is used to loosely describe any area from the urban corridor west to the Continental Divide. 
Mountains
MountainsAny location above 9,000 feet in elevation is generally considered a mountain area. There are three mountain regions in Colorado.

Northern Mountains: Mountain areas north of Interstate 70. The Flat Tops, Gore Range, Park Range, Rabbit Ears Range and the northern Front Range including Longs Peak and the Indian Peaks are all considered “Northern Mountains”. Recreational areas include Rocky Mountain National Park, Steamboat Ski Resort, and Winter Park Resort. 

Central Mountains: Mountain areas south of Interstate 70 and north of US Highway 50 are considered the “Central Mountains”. The West Elk Mountains, the Sawatch Range, the Kenosha Mountains, and the Rampart Range (including Pikes Peak) are part of the “Central Mountains”. Recreational areas include the Collegiate Peaks, Cripple Creek, and most of Colorado’s larger ski areas such as Vail, Beaver Creek, Breckenridge, Keystone, Copper and Crested Butte.

Southern Mountains: Mountain areas south of Highway 50. The San Juan Mountains and the Sangre De Cristo Mountains are considered southern mountains. Recreational areas include the Great Sand Dunes National Park & Preserve, Royal Gorge, and ski areas such Telluride, Durango, and Wolf Creek. 
Western Slope
Western-SlopeAreas of western Colorado outside of the mountains with elevations below about 7,000 feet are considered to be on the Western Slope. Examples include Grand Junction, Craig, Montrose, Durango, and Cortez. 
Continental Divide
Continental-DivideThe Continental Divide is the name of the mountain ridge that separates the watersheds that drain into the Pacific and Atlantic Oceans.

In Colorado, the Continental Divide extends from the Routt National Forest south through Rocky Mountain National Park and into the Arapaho National Forest where it crosses over Interstate 70 at the Eisenhower Tunnel. The Divide then swings through the Holy Cross Wilderness and into the San Isabel National Forest. Finally, the Divide snakes through the San Juan National Forest before dropping south into New Mexico.

The following Colorado mountain passes span the Continental Divide: Berthoud, Boreas, Fremont, Hagerman, Hoosier, Independence, La Poudre, Loveland, Monarch, Muddy, Rollins, Rabbit Ears, Tennessee, Willow Creek, and Wolf Creek.