The Colorado River drains roughly 243,000 square miles and follows a 1,450 mile course from Colorado to the Gulf of California. Diversions and dams along the river began in 1905, with the most recent completed in 1970, and numerous other dams and diversions occur on its tributaries. The combined Colorado River watershed provides essential water to roughly 40 million people in California, Nevada, Arizona, Colorado, New Mexico, Utah, Wyoming, and Mexico, and the river supports nearly every aspect of local economies, including agriculture, tourism, and generation of hydroelectric power.