El Cajon Mountain, also known as El Capitan or El Cap, is a prominent 3,677-foot summit in the Cuyamaca Mountains east of San Diego and a major East County landmark. Most of the mountain lies within Cleveland National Forest and El Capitan Open Space Preserve, but public access is tightly limited because it is nearly surrounded by private property and an Indian reservation. Its main public route from Lakeside is a class 1 hike widely considered among San Diego County’s hardest because of steep climbs and repeated elevation changes. Private, closed climbing routes on the south face and fatal accidents in 2019, 2022, and 2026 have reinforced its reputation as a formidable mountain.