Cerro Alto is a 2,624-foot mountain in San Luis Obispo County, California, whose Spanish name means “high hill.” Known for broad views, it is a popular local recreation area with several routes to the summit, including a short class-one climb, an unpaved service road, mountain-biking trails, and a nearby campground. The mountain also figured modestly in local fire management, as the U.S. Forest Service kept a fire lookout tower on the summit until 1973. From the top, visitors can see the region’s nine volcanic plugs, collectively called the Nine Sisters.