El Cajon Mountain, mountain in San Diego County, California, United States

El Cajon Mountain is a 3,677-foot summit in the Cuyamaca Mountains of San Diego County, within the Cleveland National Forest and the El Capitan County Preserve. Its slopes are covered in chaparral, coastal sage scrub and oak-lined canyons, with boulder-strewn terrain and a south face used by golden eagles for nesting.

El Cajon Mountain lies in the Cuyamaca Mountains of San Diego County, within the Cleveland National Forest and the El Capitan County Preserve. The 2,619-acre preserve holds 11 miles of trail and three unused mine shafts. San Diego Gas and Electric acquired 385 acres on the mountain in 2013 as mitigation, later held by the San Diego River Park Foundation to protect the Lakeside ceanothus.

The peak is known locally by the nickname El Cap and serves many hikers as a training ground before attempting more difficult climbs elsewhere. The climbing community in the area frequently uses it to build skills and test their abilities on varied terrain.

The climb requires thorough preparation and sufficient water for a full day of hiking. Visitors should expect long periods on the trail and account for warm conditions, especially during sunnier months.

The south face, closed to the public, holds nesting golden eagles, which is why the class 3 climbing routes there are off limits. The main trail from Lakeside is regarded as one of the hardest hikes in San Diego County, with steep climbs and rolling terrain.