San Luis Río Colorado is a municipality in Sonora state, in northwestern Mexico. The municipality is the location of the city of San Luis Rio Colorado, the community of El Golfo de Santa Clara, and the Bahia Adair biosphere preserve. Geography The municipality is in the Lower Colorado River Valley, with the Colorado River along its west, the U.S.-Mexico border along the north, and to the Colorado River Delta on the southwest, and the Gulf of California (Sea of Cortez) along the south. Adjacent jurisdictions Yuma County, Arizona — north Puerto Peñasco Municipality, Sonora — east Mexicali Municipality and Colorado River, Baja California — west Gulf of California (Sea of Cortes) — south Populated places The largest cities, towns, and villages within the municipality include: Former settlements Former historical settlements sites within the current municipality, many along the Colorado River that served shipping by steamboats on the Colorado River, include: History The first vaccines against the COVID-19 pandemic in Mexico arrived for medical personal on January 13, 2021. Eleven people were arrested for possession of weapons reserved for the military on March 13, 2021. See also Alto Golfo de California Biosphere Reserve References Municipalities of Sonora Communities in the Lower Colorado River Valley Steamboat transport on the Colorado River