Front Range Urban Corridor

The Front Range Urban Corridor is an oblong region of urban population located along the eastern face of the Southern Rocky Mountains, encompassing 18 counties in the US states of Colorado and Wyoming. The corridor derives its name from the Front Range, the mountain range that defines the western boundary of the corridor which serves as a gateway to the Rocky Mountains. The region comprises the northern portion of the Southern Rocky Mountain Front geographic area, which in turn comprises the southern portion of the Rocky Mountain Front geographic area of Canada and the United States. The Front Range Urban Corridor had a population of 5,055,344 at the 2020 census, an increase of +16.65% since the 2010 census, and a population of approximately 5.3 million as of 2025 census estimates. The corridor contains some of the West's largest cities, such as Denver and Colorado Springs. It also contains smaller but significant urban areas such as Pueblo, Fort Collins and Cheyenne. Its main transportation corridor is Interstate 25. There have been many proposals over the years for a single passenger rail connecting most of the major urban areas within the corridor, although none have come to fruition as of mid-2026. Plans are actively under development and moving forward for the Colorado Connector (CoCo), also known as the Front Range Passenger Rail. The first phase of service connecting Denver and Fort Collins could commence as soon as 2029, with full corridor service (sans Cheyenne, Wyoming) occurring just a few years after that.