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 by the Conejo Recreation and Park District (CRPD) in 1967. Trails here are available from Santa Rosa Valley, Newbury Park and Wildwood Regional Park. Although being a major feature of Wildwood, it occupies its own open-space area bordering Wildwood's northern boundaries. Mount Clef Ridge Open Space Area occupies 212 acres. From the ridge are great panoramic views of Santa Rosa Valley, Conejo Valley, Hill Canyon, as well as the Santa Susana-, Santa Monica- and Topatopa Mountains. The open-space area is home to plants such as coastal sage scrub, chaparral, Lyon's pentachaeta and Conejo dudleya. The fauna includes mountain lions, deer, coyotes, gray foxes, and more.