McElmo Creek is a 70.1-mile-long (112.8 km) tributary that joins the San Juan River in San Juan County, Utah. The creek's source is located just east of Cortez in Montezuma County, Colorado.
Geography
The creek flows westward through Montezuma County, Colorado, and into San Juan County, Utah, where it meets the San Juan River. Its drainage basin covers approximately 711 square miles (1,840 km²). The elevation at the confluence with the San Juan River is 4,462 feet (1,360 m).
Hydrology and Irrigation
The flow in McElmo Creek increased significantly after water was diverted from the Dolores River just downstream of Dolores, Colorado, through the construction of the Montezuma Tunnel in 1889. This tunnel, along with subsequent projects including Lake McPhee, was built to irrigate the dry Montezuma Valley. The irrigation resulted in new water flows entering McElmo Creek from flood irrigation wastewater, canal leakage, sluicing, and elevated groundwater levels.
Ecology and Conservation
In 2012, the U.S. Fish and Wildlife Service installed a Passive Integrated Transponder (PIT) antenna on McElmo Creek to monitor the movement of tagged endangered fish species as part of the San Juan River Recovery Program.
Cultural and Historical Features
The McElmo Creek area is archaeologically significant as part of the McElmo Drainage Unit, one of ten cultural units defined by archaeologists within the northern San Juan drainage area of the Mesa Verde region. The area was inhabited during the Great Pueblo Period (AD 1075–1300). Petroglyph panels are located approximately 16 miles west of Cortez, Colorado, along Road G, featuring images including a burro and a Spanish fighting bull.
The McElmo Creek Flume (also known as Montezuma Valley Irrigation Company Flume No. 6), built in 1921, is a historic water structure located east of Cortez on U.S. Highway 160. It was listed on the National Register of Historic Places in 2012. The flume remained operational until 1922, when the McPhee Reservoir and its laterals replaced the original irrigation system.
