San Joaquin River

San Joaquin River
San Joaquin River near Vernalis
Map of the San Joaquin River watershed
Etymology	c. 1805-1808 by Gabriel Moraga for Saint Joachim, father of Mary, the mother of Jesus
Native name	Río San Joaquín (Spanish)
Location
Country	United States
State	California
Cities	Fresno, Modesto, Stockton
Physical characteristics
Source	Thousand Island Lake[1]
• location	Ansel Adams Wilderness, Sierra Nevada
• coordinates	37°43′41″N 119°10′09″W / 37.72804°N 119.16922°W / 37.72804; -119.16922
• elevation	9,839 ft (2,999 m)
Mouth	Suisun Bay
• location	Antioch, Contra Costa/Solano Counties
• coordinates	38°04′00″N 121°51′04″W / 38.06667°N 121.85111°W / 38.06667; -121.85111[2]
• elevation	0 ft (0 m)
Length	366 mi (589 km)[3]
Basin size	15,600 sq mi (40,000 km2)[4]
Discharge
• location	Vernalis, 78 mi (126 km) from the mouth[5]
• average	5,110 cu ft/s (145 m3/s)[5]
• minimum	30 cu ft/s (0.85 m3/s)
• maximum	325,000 cu ft/s (9,200 m3/s)[6]
Basin features
Tributaries
• left	Fresno Slough
• right	Merced River, Tuolumne River, Stanislaus River, Mokelumne River

The San Joaquin River (/ˌsæn hwɑːˈkiːn/; Spanish: Río San Joaquín) is the longest river of Central California. The 366-mile (589 km) long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean. An important source of irrigation water as well as a wildlife corridor, the San Joaquin is among the most heavily dammed and diverted of California's rivers.

People have inhabited the San Joaquin Valley for more than 8,000 years, and it was long one of the major population centers of pre-Columbian California. Starting in the late 18th century, successive waves of explorers then settlers, mainly Spanish and American, emigrated to the San Joaquin basin. When Spain colonized the area, they sent soldiers from Mexico, who were usually of mixed native Mexican and Spanish birth, led by Spanish officers. Franciscan missionaries from Spain came with the expeditions to evangelize the natives by teaching them about the Catholic faith.

Once an inland sea,^[7] most of the San Joaquin Valley has a very uniform topography, and much of the lower river formed a huge flood basin.^[8] In the 20th century, many levees and dams were built on the San Joaquin and all of its major tributaries. These engineering works changed the fluctuating nature of the river forever, and cut off the Tulare Basin from the rest of the San Joaquin watershed. Once habitat for hundreds of thousands of spawning salmon and millions of migratory birds, today the river is subject to tremendous water-supply, navigation and regulation works by various federal agencies, which have dramatically reduced the flow of the river since the 20th century.