Dividing the drainages of the Manzana and Sisquoc is a ridge known as Hurricane Deck, a rugged 15-mile (24 km) slab of upthrust sandstone with a trail snaking along the top.

Both the Nacimiento and Big Pine Faults run through the wilderness, roughly parallelling the Sierra Madre and San Rafael Mountain crests respectively.

Immediately south of the wilderness, opposite the Big Pine and Camuesa Faults, is a large region of the Franciscan Formation.

The typical vegetation in the wilderness is chaparral and oak woodland, although there are stands of pine and fir at higher elevations and on north-facing slopes, as well as riparian forests in the streams.

[6] The wilderness is often closed to entry during fire season, the exact dates of which vary but usually include the late summer and early fall.

Due to a disagreement between the Forest Service, US Congress and conservationists over 2,200 acres (8.9 km2) of natural grass openings called portreros, which contained pictographs from the Chumash Indians, it took a long time for the wilderness designation.

[7] In 1992, after the passage of the Los Padres Condor Range and River Protection Act, Congress added an additional 48,210 acres (195 km2) adjacent to the original area on the northwest.