Devil's Slide Bunker

Devil's Slide is a name given to a steep, rocky coastal promontory located about midway between Montara and the Linda Mar District of Pacifica. The terrain is characterized by steep, eroded slopes with natural gradients ranging between 30 and 70%. There are small coastal valleys throughout along the major drainages within the Montara Mountain watershed. The soils in these valleys are deep and moderately well drained and have developed along the low terraces and alluvial fans of the stream channels. Devil's Slide was the location of a military triangulation station and observation site used during World War II as part of the harbor defense of San Francisco. Prior to the advent of radar, military personnel would use binoculars and compasses to search for ships at sea and relay their coordinates to a central post. By combining information from multiple observation posts, a ship's precise location could be determined by triangulation. There were six military structures at the Devil's Slide: three concrete and steel observation pill-boxes, two concrete and earth bunkers, and a reinforced steel observation tower. The pill-boxes were used as hardened observation posts, and one of the bunkers was used as a communications and command post. The site was sold to a private owner in 1983, but some of the structures remain. The climate of the area is Mediterranean with a strong maritime influence. The temperature range is narrow both seasonally and diurnally, while air moisture is relatively high. Extremely dense northern coastal scrub covers most of the locale, especially over San Pedro Mountain and along the steeper foot slopes of Montara Mountain. Small grassy openings and barren rocky areas are scattered throughout the scrub areas. The inland area holds other types of vegetation including, aquatic and coastal freshwater marshes/seeps, willow riparian scrub, coastal grassland, non-native forest, and pasture/ranch uses/non-native brushland. The endangered species Hickman's potentilla occurs on the slopes above Martini Creek at up to 430 feet (130 m) elevation.