Hill Canyon is a deep canyon in the western Simi Hills, located within northern Newbury Park and Thousand Oaks, in Ventura County, southern California. It is part of the Conejo Canyons Open Space and includes the Arroyo Conejo Nature Preserve.
Geography
The canyon separates the Conejo Grade area and westernmost Simi Hills from the Mount Clef Ridge to the east. It was formed by Arroyo Conejo (creek) flowing down from the higher Conejo Valley to the lower Santa Rosa Valley, where the creek merges with Arroyo Santa Rosa and becomes Conejo Creek. The canyon is situated east of the Conejo Grade in Camarillo and immediately west of the Mount Clef Ridge of Wildwood Regional Park in Thousand Oaks.
The area is locally known as La Barranca (Spanish for "canyon").
Features
Hill Canyon is a deeply eroded canyon at the foothills of dramatic ridgelines and volcanic outcroppings on the Mount Clef Ridge. The Conejo Canyons collectively make up 1,628 acres. The flora includes coast live oak and riparian woodlands, coastal sage scrub, interior sage scrub, and chaparral. From nearby peaks, there are panoramic views extending to the Pacific Ocean, the Oxnard Plain, and the Topatopa Mountains.
Hill Canyon Wastewater Treatment Plant
The only developed area in the canyon is the Hill Canyon Wastewater Treatment Plant (HCTP), which occupies approximately 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 annually for processing. The plant transforms wastewater into reusable water through advanced tertiary treatment.
Trails and Recreation
Hill Canyon Trail is the primary trail and connects to several other trails, including:
- Hawk Canyon Trail
- Western Plateau Trail
- Arroyo Conejo Trail
- Lynnmere Trail
- Canyon Overlook Trail (which climbs to the top of Mount Clef Ridge from Santa Rosa Valley)
Trails are accessible from trailheads in Wildwood Regional Park, Rancho Conejo Playfields, and Santa Rosa County Park. The trails are used for hiking, mountain biking, running, and horseback riding. Once slated for a golf course, the canyon is now protected open space.
Conservation
The canyon is owned and operated by the Conejo Open Space Foundation (COSF). The Arroyo Conejo Nature Preserve includes the central canyon area and is part of the Conejo Canyons Open Space system.
