Arroyo Conejo Open Space

File:Hill-Canyon-Wastewater-Plant-Wetlands-Newbury-Park.jpgs in Hill Canyon]]

The preserve is often locally referred to as La Branca or the Barranca (Spanish for "the canyon"),{{cite web |title=Conejo Open Space Conservation Agency |url=http://www.conejo-openspace.org/open_space_areas_in_TO.htm#Arroyo |archive-url=https://web.archive.org/web/20160209163754/http://conejo-openspace.org/open_space_areas_in_TO.htm#Arroyo |archive-date=2016-02-09 }}{{Cite web |url=http://www.theacorn.com/news/2001-01-18/Columns/50.html |title=There Goes the Neighborhood! | January 18, 2001 | www.theacorn.com | The Acorn |access-date=2016-03-10 |archive-url=https://web.archive.org/web/20160310134413/http://www.theacorn.com/news/2001-01-18/Columns/50.html |archive-date=2016-03-10 |url-status=dead }} and is nicknamed the Grand Canyon of the Conejo Valley.{{Cite web|url=https://www.latimes.com/archives/la-xpm-1990-11-05-me-2887-story.html|title = Designer Leads the Crusade to Save a Canyon : Thousand Oaks: Mark Murphy hopes the city will join his fight to clean up and preserve La Barranca, a 3-mile gorge threatened by development. |last=Pascual |first=Psyche |website = Los Angeles Times| date=5 November 1990 }} Its stated purpose is "the preservation of the scenic areas, natural habitats, wildlife, archaeological and paleontological sites of the Conejo Valley and surroundings, specifically including the Arroyo Conejo". It contains 250 acres of land and has been administrated and owned by the Conejo Open Space Conservation Agency (COSCA) since its incorporation in July 1977.{{cite web |title=Air Quality, Greenhouse Gas (GHG) and Fuel Use |url=http://doorstoarrival.com/wp-content/uploads/2015/10/SierraClubComments-FAA-SoCal-EA-Metroplex.pdf |publisher=Sierra Club - Angeles Chapter |archive-url=https://web.archive.org/web/20190726215201/http://doorstoarrival.com/wp-content/uploads/2015/10/SierraClubComments-FAA-SoCal-EA-Metroplex.pdf |archive-date=2019-07-26 |date=2015-10-08}} La Branca is a narrow ravine or gorge that runs three miles from northern Newbury Park near the Rancho Conejo Playfields, to Hill Canyon near the Hill Canyon Wastewater Treatment Plant in the Conejo Canyons Open Space.

La Branca has a gorge section with cliffs rising up to {{convert|300|ft}}. The preserve is home to large variety of plant- and animal species, including for instance southwestern pond turtles, mountain lions, bobcats, black bears, deer, coyotes, and avifauna such as quails, golden eagles, hawks, owls, and numerous others.{{cite web|url=http://smmc.ca.gov/pdf/attachment70_Attachment.pdf |title=Conserve our Rural Environment |date=2005-02-15 |access-date=2016-03-10 |url-status=dead |archive-url=https://web.archive.org/web/20101102023047/http://smmc.ca.gov/pdf/attachment70_Attachment.pdf |archive-date=2010-11-02 }} (Page 1). It contains the perennial South Fork of the Arroyo Conejo, riparian zone vegetation, steep-sided canyons, California oak woodlands, as well as wetlands.

The Hill Canyon Wastewater Treatment Plant has the largest constructed wetlands in Ventura County, within approximately {{convert|15|acres}} of the Arroyo Conejo Nature Preserve. Natures Image has helped create this area by removal of invasive plant species, as well as the planting of 1,600 native trees, 7,000 emergent marsh plants, 6,000 low herbaceous wetland plants, and 1,200 riparian scrub plants. The area is home to the endemic Southwestern Pond Turtle, as well as large numbers of mallards, coots, herons, and numerous other species of freshwater fish and birds.{{cite web|url=http://www.naturesimage.net/pdfs/naturesimage-casestudy-hill-canyon-restoration.pdf |title=Hill Canyon Wetlands Restoration |access-date=2016-03-10 |url-status=dead |archive-url=https://web.archive.org/web/20160310132742/http://www.naturesimage.net/pdfs/naturesimage-casestudy-hill-canyon-restoration.pdf |archive-date=2016-03-10 }}

The nature preserve was highlighted in the Conservation Element of the General Plan in 1972 and later identified in the City's Conejo Canyons Study of 1976 as an area with particularly sensitive and important resources. The president of the Conejo Valley Audubon Society met with representatives from The Nature Conservancy in 1974. One visitor during these meetings mentioned how incredible it was to "find such a primordial setting within the city limits of a Los Angeles bedroom community."Maxwell, Thomas J. (2000). Hiking In Wildwood Regional Park: Natural History, Folklore, and Trail Guide. California Lutheran University (CLU). Page 181. On July 1, 1976, the Thousand Oaks-based News-Chronicle reported the formation of a Small Wilderness Area Preserves chapter to protect donated Canyon lands. Arroyo Conejo Nature Preserve was incorporated and organized in lieu of the Small Wilderness Group in July 1977.

• Wildwood Regional Park
• Conejo Canyons Open Space
• {{C|Simi Hills|Simi Hills topics}}

{{Reflist|33em}}{{Protected areas of California}}

Category:Nature reserves in California

Category:Parks in Ventura County, California

Category:Simi Hills

Category:Conejo Valley

Category:Geography of Thousand Oaks, California

Category:Newbury Park, California

Category:Protected areas of Ventura County, California

Category:Protected areas established in 1977

Category:1977 establishments in California