Poso Creek or Posey Creek is an intermittent stream in

Kern County, California Kern County is a county (United States), county located in the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 909,235. Its county seat is Bakersfield, California, Bakersfield. Kern County comprise ...

. The headwaters of Poso Creek are located within the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

and the

Sequoia National Forest Sequoia National Forest is located in the southern Sierra Nevada mountains of California. The U.S. National Forest is named for the majestic Giant Sequoia (''Sequoiadendron giganteum'') trees which populate 38 distinct groves within the boundar ...

, at elevations of up to . The high Spear Creek Falls (often known as Poso Creek Falls) is located along a tributary of Poso Creek within the national forest. Poso Creek proper begins at the confluence of Spear Creek and Von Hellem Creek on the west slope of the

Greenhorn Mountains The Greenhorn Mountains are a mountain range of the Southern Sierra Nevada, in California. They are protected within the Sequoia National Forest. Geography The range is located in eastern Kern County and Tulare County. They are east of the San ...

. The upper reaches of the creek flow south through the Linn Valley past Posey and Glennville, then to Poso Flat, where it receives Cedar Creek and Little Poso Creek from the east. Below the confluence with Little Poso Creek, it turns west, passing through the Mount Poso and Poso Creek oil fields, which are a likely source of petroleum pollutants during flooding events. Below the oil fields the creek emerges to the intensively farmed

San Joaquin Valley The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven c ...

, where it passes between

Wasco Wasco is the name of four places in the United States: Places United States * Wasco, California, a city in California ** Wasco State Prison, located in Wasco, California * Wasco, Illinois, a former hamlet (unincorporated town) in Illinois, now pa ...

and McFarland. The creek is crossed by

Highway 99 International * European route E99 Australia * Springbrook Road, Queensland Canada * British Columbia Highway 99 * Ontario Highway 99 (former) * Saskatchewan Highway 99 China * G99 Expressway India * National Highway 99 (India) ...

and the

Southern Pacific Railroad The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...

at Famoso and by the

Friant-Kern Canal The Friant-Kern Canal is a aqueduct (water supply), aqueduct managed by the United States Bureau of Reclamation in Central California to convey water to augment irrigation capacity in Fresno County, California, Fresno, Tulare County, California, ...

a few miles downstream. Most of the lower creek flows through artificial channels beginning north of Wasco. Its mouth is on the

Kern River The Kern River, previously Rio de San Felipe, later La Porciuncula, is an Endangered, Wild and Scenic river in the U.S. state of California, approximately long. It drains an area of the southern Sierra Nevada mountains northeast of Bakersfiel ...

floodway in

Kern National Wildlife Refuge Kern National Wildlife Refuge is a protected area located in the southern portion of California's San Joaquin Valley, 20 miles west of the city of Delano. Situated on the southern margin of what was once the largest freshwater wetland complex in ...

, which connects the normally dry Buena Vista Lake with Tulare Lake. As a primarily rain fed stream, Poso Creek flows only seasonally (November to May) in its upper reaches, while the lower part is an

ephemeral Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, fr ...

wash. The

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

operated a stream gage on Poso Creek from 1959 to 1985, recording an average annual flow of . The greatest flow was on February 25, 1969, while the creek was dry for six straight months in 1977.

Luxilis occidentalis

Poso Creek (or 0-co-ya, creek) is the only place that the fish ''Luxilis occidentalis'' is known to have lived except for Four Creeks in the Tulare Valley. It was collected here in 1855 by Dr A.L. Heerman.

References

{{Tulare Basin Hydrography, state=collapsed Rivers of the Sierra Nevada (United States) Rivers of Kern County, California Kern River Tulare Basin watershed Greenhorn Mountains Central Valley Project History of Kern County, California Pre-statehood history of California History of Southern California Rivers of Southern California Rivers of the Sierra Nevada in California