South Platte River - Description

Description

The river is formed in Park County, Colorado, southwest of Denver in the South Park grassland basin by the confluence of the South Fork and Middle Fork, approximately 15 miles (24 km) southeast of Fairplay. Both forks rise along the eastern flank of the Mosquito Range, on the western side of South Park, which is drained by the tributaries at the headwaters of the river. From South Park, it passes through 50 miles (80 km) of the Platte Canyon and its lower section, Waterton Canyon. Here, it is joined by the North Fork before emerging from the foothills southwest of the Denver suburb of Littleton. At Littleton, the river is impounded to form Chatfield Reservoir, a major source of drinking water for the Denver Metropolitan Area.

The river flows north through central Denver, which was founded along its banks at its confluence with Cherry Creek. The valley through Denver is highly industrialized, serving generally as the route for both the railroad lines, as well as Interstate 25. On the north side of Denver it is joined somewhat inconspicuously by Clear Creek, which descends from the mountains to the west in a canyon that was the cradle of the Pike's Peak Gold Rush. North of Denver it flows through the agricultural heartland of the Piedmont (a shale region that was formed through erosion by the ancestor of the river following the creation of the Rockies). It flows directly past the communities of Brighton and Fort Lupton, and is joined in succession by Saint Vrain Creek, the Little Thompson River, the Big Thompson River, and the Cache la Poudre River, which it receives just east of Greeley.

East of Greeley it turns eastward, flowing across the Colorado Eastern Plains, past Fort Morgan and Brush, where it turns northeastward. It continues past Sterling, and runs into Nebraska between Julesburg, Colorado and Big Springs, Nebraska. In Nebraska, it passes south of Ogallala and joins the North Platte River near the city of North Platte.

The South Platte River through Denver is on the U.S. EPA's list of impaired waterbodies for pathogen impairment, with E. coli as the representative pathogen species. Other water issues involve the appearance of the New Zealand Mud Snail and of the Zebra Mussel.