Those who have never visited Denver, Colorado, tend to assume that it is surrounded by mountains. In fact, the city stretches along the base of the Front Range (to its west) and its topography consists primarily of two valleys that merge in the downtown area and then continue northward as a single, broad valley.
The Front Range and its foothills are the most prominent geographic feature of Metro Denver but one also notices a ridge of high ground to the south. This ridge, now occupied by Highlands Ranch, Lone Tree and Castle Pines, extends northward through Centennial and the Denver Tech Center (along Interstate 25); it divides the Cherry Creek Valley, to the east, from the Plum Creek-South Platte Valley to the west. The upper tributaries of Cherry Creek and Plum Creek rise along the north side of the Palmer Divide; the latter is a high ridge that stretches west to east between Denver and Colorado Springs, dividing the watersheds of the South Platte River ( to the north) from that of the Arkansas River (to the south).
The South Platte rises in the mountains southwest of Denver and exits the foothills via Waterton Canyon, in southwest Metro Denver. Within a mile, the River enters Chatfield Reservoir where it receives the flow from Plum Creek. Below that reservoir, the South Platte flows NNE through Metro Denver, receiving several tributaries from the mountains and merging with Cherry Creek at Confluence Park in downtown Denver. North of the city, the South Platte River continues northward and then northeastward, taking in many more tributaries from the Front Range and from the High Plains of northeastern Colorado.
