Casa de Oro-Mount Helix

The CDP encompasses several unincorporated neighborhoods east of La Mesa and south of El Cajon, principally the communities of Mount Helix and Casa de Oro. Much of the area lies within the County of San Diego’s Valle de Oro Community Planning Area, which identifies Casa de Oro, Mount Helix, Vista Grande Hills, and Rancho San Diego as neighborhoods within the planning area."Valle de Oro Community Plan". County of San Diego. Planning & Development Services. Retrieved August 23, 2026. County planning documents also refer collectively to the “Mt. Helix/Casa de Oro Area”, with lower-density residential development extending from the Casa de Oro area northward onto the slopes of Mount Helix."Valle de Oro Community Plan" (PDF). County of San Diego. Planning & Development Services. Retrieved August 23, 2026.

Mount Helix developed during the early 20th century as a semi-rural residential community characterized by orchards, large homesites, and estate properties. Developer Ed Fletcher acquired Mount Helix and developed it as an exclusive residential community."God's Garden: A History of the Point Loma Theosophical Community". The Journal of San Diego History. San Diego History Center.