State Route 166 (SR 166) is a

state highway A state highway, state road, or state route (and the equivalent provincial highway, provincial road, or provincial route) is usually a road that is either ''numbered'' or ''maintained'' by a sub-national state or province. A road numbered by a ...

in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. It connects the Central Coast to the southern

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 ...

, running from State Route 1 in Guadalupe and through Santa Maria in

Santa Barbara County Santa Barbara County, California, officially the County of Santa Barbara, is located in Southern California. As of the 2020 census, the population was 448,229. The county seat is Santa Barbara, and the largest city is Santa Maria. Santa Barba ...

to State Route 99 in Mettler in

Kern County Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield. Kern County comprises the Bakersfield, California, Metropolitan statistical area. The county sp ...

Route description

SR 166 heading into Maricopa, California

Route 166 starts off in Guadalupe in northwestern

and heads east towards Santa Maria, the largest city on its eastern journey. It then joins with

U.S. Route 101 U.S. Route 101, or U.S. Highway 101 (US 101), is a north–south United States Numbered Highway that runs through the states of California, Oregon, and Washington, on the West Coast of the United States. It is also known as (The Royal Roa ...

for the last few miles in Santa Barbara County before crossing the Santa Maria River and splitting off in

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra founded the Miss ...

. For the next , SR 166 crosses the Santa Barbara/San Luis Obispo county line a total of five times. This stretch follows the

Cuyama River The Cuyama River (Chumash: ''Kuyam'', meaning "Clam") is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed March 15, 2011 river in southern San Luis Obispo County, northern Santa Barbara ...

through a canyon separating the Sierra Madre Mountains from mountains in San Luis Obispo County, and then opens out into the

Cuyama Valley The Cuyama Valley (Chumash: ''Kuyam'', meaning "Clam") is a valley along the Cuyama River in central California, in northern Santa Barbara, southern San Luis Obispo, southwestern Kern, and northwestern Ventura counties. It is about two hours ...

, passing cattle ranches, going through the

Russell Ranch Oil Field The Russell Ranch Oil Field is an oil and gas field in the Cuyama Valley of northern Santa Barbara and southern San Luis Obispo Counties, California, in the United States. Discovered in 1948, and reaching peak production in 1950, it has produced ...

, and passing Aliso Canyon Road, the turnoff to the

South Cuyama Oil Field The South Cuyama Oil Field is a large oil and gas field in the Cuyama Valley and the adjacent northern foothills of the Sierra Madre Mountains in northeastern Santa Barbara County, California. Discovered in 1949, and with a cumulative production ...

. On the north during this stretch is the mile-high

Caliente Range The Caliente Range is a west-east trending zone of uplift mountains in the California Coast Ranges, in central California. The highest peak of the range is Caliente Mountain at in elevation, located in southeastern San Luis Obispo County. Geology ...

, which contains

Caliente Mountain Caliente Mountain is a mountain located in the Southern Coast Ranges of California and is a federally listed wilderness study area for more than 30 years. The summit, at , is the highest point in San Luis Obispo County and the Caliente Range. The ...

, the highest peak in San Luis Obispo County. After going through the towns of

New Cuyama New is an adjective referring to something recently made, discovered, or created. New or NEW may refer to: Music * New, singer of K-pop group The Boyz Albums and EPs * ''New'' (album), by Paul McCartney, 2013 * ''New'' (EP), by Regurgitator, ...

and Cuyama, the highway meets SR 33 north of Ventucopa. SR 33 and SR 166 merge until reaching

Maricopa Maricopa can refer to: Places * Maricopa, Arizona, United States, a city ** Maricopa Freeway, a piece of I-10 in Metropolitan Phoenix ** Maricopa station, an Amtrak station in Maricopa, Arizona * Maricopa County, Arizona, United States * Marico ...

, where SR 166 heads due east for its last , intersecting with

I-5 Interstate 5 (I-5) is the main north–south Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada. It travels through the states of Californi ...

about north of the

Grapevine ''Vitis'' (grapevine) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, ...

. SR 166 ends at SR 99 in Mettler, and it is the last exit for both I-5 and SR 99 southbound before they merge near

Wheeler Ridge Wheeler Ridge is an unincorporated area, unincorporated community in the southwestern San Joaquin Valley, within Kern County, California, Kern County, California. It is at the junction of the valley floor and the Wheeler Ridge landform of the Te ...

. In

, Highway 166 is known as the Maricopa Highway. West of Maricopa, where it skirts Santa Barbara and San Luis Obispo counties, it is called the Cuyama Highway. In the cities of Santa Maria and Guadalupe, it is known as Main Street. SR 166 is part of the

California Freeway and Expressway System The California Freeway and Expressway System is a system of existing or planned freeways and expressways in the U.S. state of California. It encompasses both State highways and federal highways in California. It is defined by Article 2 (commenci ...

, but is not part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the

Federal Highway Administration The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program a ...

. The route is eligible for the State Scenic Highway System, but it is not officially designated as a scenic highway by the

California Department of Transportation The California Department of Transportation (Caltrans) is an executive department of the U.S. state of California. The department is part of the cabinet-level California State Transportation Agency (CalSTA). Caltrans is headquartered in Sacrame ...

. From

US 101 U.S. Route 101, or U.S. Highway 101 (US 101), is a north–south United States Numbered Highway that runs through the states of California, Oregon, and Washington, on the West Coast of the United States. It is also known as (The Royal Roa ...

to SR 33, SR 166 is known as the "CHP Officers Irvine and Stovall Memorial Highway". In February 1998, a large storm swelled the Cuyama River and caused it to wash out a section of the highway. Officers Britt Irvine and Rick Stovall were responding to an early morning call about a truck accident when their CHP cruiser drove off the washed out section.

History

Before 1964, the portion of SR 166 merged with SR 33 was part of US 399.

Major intersections

References

External links

{{commonscat
California @ AARoads.com - State Route 166Caltrans: Route 166 highway conditions
166 State Route 166 State Route 166 State Route 166 Cuyama Valley

Route description

History

Major intersections

See also

References

External links