San Diego River

San Diego River
Looking upstream near mouth
Location of the mouth of the San Diego River in California
Location
Country	United States
State	California
Region	San Diego County
Physical characteristics
Source	Cuyamaca Mountains
• location	5 miles (8 km) northwest of Julian, California
• coordinates	33°07′09″N 116°39′00″W / 33.11917°N 116.65000°W / 33.11917; -116.65000[1]
• elevation	3,750 ft (1,140 m)
Mouth	Mission Bay
• location	Community of Ocean Beach, San Diego, California
• coordinates	32°45′37″N 117°12′45″W / 32.76028°N 117.21250°W / 32.76028; -117.21250[1]
• elevation	13 ft (4.0 m)[1]
Length	52 mi (84 km)
Basin size	420 sq mi (1,100 km2)[2]
Discharge
• average	38.3 cu ft/s (1.08 m3/s)
• minimum	0 cu ft/s (0 m3/s)
• maximum	94,500 cu ft/s (2,680 m3/s)

The San Diego River is a river in San Diego County, California. It originates in the Cuyamaca Mountains northwest of the town of Julian, then flows to the southwest until it reaches the El Capitan Reservoir, the second-largest reservoir in the river's watershed at 112,800 acre-feet (139,100,000 m³). Below El Capitan Dam, the river runs west through Santee and San Diego. While passing through Tierrasanta it goes through Mission Trails Regional Park, one of the largest urban parks in America.

It flows near the Mission San Diego de Alcalá. The river's valley downstream from there is known as Mission Valley for that reason. The valley forms a transportation corridor for Interstate 8 and for the San Diego Trolley Green Line. The river discharges into the Pacific Ocean near the entrance to Mission Bay, forming an estuary.