pedestrians and bicyclists, taking over the section of roadway formerly used by State Route 1 and now bypassed by the new tunnels. The total cost to convert the highway into a trail was . In popular culture Devil's Slide was used in a key scene of the 1960 thriller Portrait in Black with Lana Turner and Anthony Quinn. Turner and Quinn portrayed doomed lovers who deliberately pushed a car, containing the body of a murdered man, over the edge of the cliff. The Universal crew obtained permission from the State of California to stage the scene, which involved retrieving the car from the bottom of the cliff once the scene had been successfully filmed. The San Mateo Times printed a photograph of the filming of this sequence. Military history 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 used 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 southernmost bunker site was sold to a private owner in 1983, but some of the exposed structure remains. See also Salinian Block Coastal erosion California landslides Bibliography Biological Assessment, Species of Concern, Proposed Route 1 Devil's Slide Tunnel Bypass Project, San Mateo County, California Prepared by Caltrans, Office of Environmental Planning, South. July, 1998. Michael Hogan and Ballard George, Air Quality and Noise Analyses for the Bypass Alternative, Devil's Slide Improvement Project, Caltrans District 4, prepared by Earth Metrics Inc., Burlingame, CA (1984) Devil's Slide Improvement Project, San Mateo County, California, Draft Second Supplemental Environmental Impact Statement, Caltrans District 4 (1999) Hovland, John H., Ph.D., P.E., A Study of the Feasibility of Stabilizing the Landslide Area Along Highway One, San Mateo County, California, by Dewatering, April, 1998 Woodward-Clyde Consultants, Devil’s Slide Tunnel Study - Feasibility Report, October, 1996. Footnotes External links California Coastal Commission Three-part series on the history of Devil's Slide KQED QUEST photo montage