Hill Canyon is a deep

canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...

in the western

Simi Hills The Simi Hills are a low rocky mountain range of the Transverse Ranges in eastern Ventura County and western Los Angeles County, of southern California, United States. Geography The Simi Hills are aligned east-west and run for , and average arou ...

and within northern Newbury Park and

Thousand Oaks Thousand Oaks is the second-largest city in Ventura County, California, United States. It is in the northwestern part of Greater Los Angeles, approximately from the city of Los Angeles and from Downtown. It is named after the many oak tree ...

, in

Ventura County Ventura County () is a county in the southern part of the U.S. state of California. As of the 2020 census, the population was 843,843. The largest city is Oxnard, and the county seat is the city of Ventura. Ventura County comprises the Oxnar ...

southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

. The

Arroyo Conejo Nature Preserve Arroyo Conejo Open Space is a open space reserve in the western Simi Hills in northern Newbury Park, Ventura County, California. Most of it is part of the Arroyo Conejo Nature Preserve (sometimes shortened to the Arroyo Nature Preserve). Geog ...

includes the central canyon area, and is part of the

Conejo Canyons Open Space The Conejo Canyons Open Space consists of of open-space areas in northernmost Newbury Park, Ventura County, California. It consists of deeply eroded canyons, numerous ridgelines and plateaus in the northwestern portion of the Conejo Valley. The ...

. It has trails connecting it to

Santa Rosa Valley The Santa Rosa Valley is a small valley and rural unincorporated community in Ventura County, Southern California. The valley is about long (east to west) and wide (north to south). Although not within its city limits, the community is someti ...

County Park at the canyon's mouth, to

Wildwood Regional Park Wildwood Regional Park is a suburban regional park in the western Simi Hills and Conejo Valley, in Ventura County, California. It is located in western Thousand Oaks, northern Newbury Park, and southern Moorpark. Wildwood is home to over 27 mi ...

east of the canyon, and to

Rancho Conejo Playfields Rancho Conejo Playfields is a multi-use community park in Newbury Park, California, adjacent to Conejo Canyons Open Space and the Arroyo Conejo Nature Preserve which includes of public open-space land and numerous trails in the western Simi Hi ...

southwest of the canyon.

Geography

The canyon separates the

Conejo Grade The Conejo Grade is a 7% grade incline on a section of US 101 (the Ventura Freeway). Also known as the Camarillo Grade, it links Thousand Oaks and cities of the Conejo Valley, with Camarillo and the cities on the Oxnard Plain. With a summit elev ...

area and westernmost Simi Hills from the

Mount Clef Ridge Mount Clef Ridge is a 1,076 ft volcanic mountain in Thousand Oaks, California. It is a volcanic outcrop that resulted from lava eruptions 30 million years ago. The ridge was formerly under ownership by the Janss Corporation, but was acquired ...

to the east. It was formed by

Arroyo Conejo Arroyo Conejo (Spanish for “Rabbit Creek”) is the longest creek in the Conejo Valley, sprawling over the cities of Thousand Oaks and Camarillo, and the communities of Newbury Park, Casa Conejo and Santa Rosa Valley. Arroyo Conejo is the pri ...

(creek) flowing down through the Simis from the higher

Conejo Valley The Conejo Valley is a region spanning both southeastern Ventura County and northwestern Los Angeles County in Southern California, United States. It is located in the northwestern part of the Greater Los Angeles Area. Communities in the Conejo ...

to the lower

, where the creek merges with Arroyo Santa Rosa and becomes Conejo Creek. It is located in an area locally known as '' La Barranca'' (Spanish for canyon). It is a deeply eroded canyon at the foothills of dramatic ridgelines and volcanic outcroppings on the Mount Clef Ridge. Hill Canyon is part of the

, which is owned and operated by the Conejo Open Space Foundation (COSF). The canyon is situated east of the Conejo Grade in

Camarillo, CA Camarillo ( ) is a city in Ventura County in the U.S. state of California. As of the 2020 United States Census, the population was 70,741, an increase of 5,540 from the 65,201 counted in the 2010 Census. Camarillo is named for brothers Juan an ...

, and is immediately west of the Mount Clef Ridge of

. Once slated for a golf course, the canyon is now protected open space. Hiking trails and bridges are accessible from trailheads found for instance in Wildwood Regional Park,

and Santa Rosa County Park. Hill Canyon Trail is the primary trail and connects to the Hawk Canyon Trail, Western Plateau Trail, Arroyo Conejo Trail, Lynnmere Trail, and the Canyon Overlook Trail, which climbs to the top of the Mount Clef Ridge from Santa Rosa Valley. The only developed area in Hill Canyon is the Hill Canyon Wastewater Treatment Plant (HCTP), which takes up about sixty acres and includes the largest bodies of water in Newbury Park. It has a capacity of 14,000,000 gallons per day, and approximately 3.7 billion gallons of water are conveyed here every year for processing. Thousands of gallons in sewage spills have led to leaks into the adjacent

Conejo Creek Arroyo Conejo (Spanish for “Rabbit Creek”) is the longest creek in the Conejo Valley, sprawling over the cities of Thousand Oaks and Camarillo, and the communities of Newbury Park, Casa Conejo and Santa Rosa Valley. Arroyo Conejo is the prim ...

, which discharges at its

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

Mugu Lagoon Mugu Lagoon (; Chumash: ''Muwu'', meaning "Beach") is a salt marsh located within the Naval Base Ventura County at the foot of the Santa Monica Mountains in Ventura County, California. The lagoon extends for 4.3 miles parallel to a narrow barrier ...

. The

Conejo Canyons The Conejo Canyons Open Space consists of of open-space areas in northernmost Newbury Park, Ventura County, California. It consists of deeply eroded canyons, numerous ridgelines and plateaus in the northwestern portion of the Conejo Valley. The ...

make up a total of 1,628 acres when combined together. The flora includes

coast live oak ''Quercus agrifolia'', the California live oak, or coast live oak, is a highly variable, often evergreen oak tree, a type of live oak, native to the California Floristic Province. It may be shrubby, depending on age and growing location, but is g ...

- and

riparian woodland A riparian forest or riparian woodland is a forested or wooded area of land adjacent to a body of water such as a river, stream, pond, lake, marshland, estuary, canal, sink or reservoir. Etymology The term riparian comes from the Latin word ' ...

coastal sage scrub Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is w ...

, as well as interior sage scrub and

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

. From nearby peaks there are panoramic views as far as the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, the

Oxnard Plain The Oxnard Plain is a large coastal plain in southwest Ventura County, California, United States surrounded by the mountains of the Transverse ranges. The cities of Oxnard, Camarillo, Port Hueneme and much of Ventura as well as the unincorpora ...

, and the

Topatopa Mountains The Topatopa Mountains are a mountain range in Ventura County, California, north of Ojai, Santa Paula, and Fillmore. They are part of the Transverse Ranges of Southern California. Etymology A name for the mountains was first inscribed within the ...

. The trails here are used for horseback-riding, mountain biking, running and hiking.Murphy, Kelly (2012). ''Local Multi-Use Trails''. Kelly Murphy. Page 118. .

References

{{coord missing, Ventura County, California Canyons and gorges of California Simi Hills Landforms of Ventura County, California Conejo Valley Geography of Thousand Oaks, California Newbury Park, California Protected areas of Ventura County, California

Geography

See also

References