|Topa Topa Mountains|
|Elevation||6,738 ft (2,054 m)|
|Coordinates||34°31′48″N 119°02′35″W / 34.530°N 119.043°WCoordinates: 34°31′48″N 119°02′35″W / 34.530°N 119.043°W|
|Parent range||Transverse Ranges|
|Borders on||Sierra Pelona Mountains and Sierra Madre 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.
A name for the mountains was first inscribed within the archives of Mission Basilica San Buenaventura in 1943, citing a nearby Chumash ranchería named "Si-toptopo". In 1945, American linguist and ethnologist John Peabody Harrington noted that "topa" is a Chumash word meaning "reed" or "rush".
The Topatopa Mountains lie in an east–west direction east of the Sierra Madre Mountains, and west of the Sierra Pelona Mountains. To the south lies the Santa Clara River Valley into which various creeks drain starting in the mountains into the Santa Clara River. The range reaches an elevation of 6,738 feet (2,054 m) at Cobblestone Mountain, about 14 mi (23 km) north-northeast of Fillmore and about 16 mi (26 km) northwest of Castaic. Snow frequently falls on the high peaks during winter.
Several major tributaries of the Santa Clara River flow down from the Topatopa Mountains, the largest being Piru Creek and Sespe Creek.
Lake Piru is the only major reservoir located within the mountains.
The Topatopa Mountains are within the southern Los Padres National Forest. The Sespe Wilderness Area, and the Sespe Condor Sanctuary, are primarily within the Topatopa Mountains and foothills. They are part of the home range of the endangered California condor.
The habitat is of the California montane chaparral and woodlands ecoregion. Sespe Creek flows through the range, creating Sespe Gorge, with Riparian habitats of willows and woodlands.