History of Oceanside The northernmost coastal city in San Diego County, Oceanside is a beach community with over 3 ½ miles of coastline, a fine small-craft harbor housing 900 pleasure boats, sport fishing operations, shops and restaurants.

Oceanside lies in the agriculture-rich San Luis Rey Valley, which was first explored by the Spanish Explorer Portola in 1769, followed by Mission construction in 1798. The Mission, with its vast fruit orchards and cattle raising activities included a large population of Luiseno Indians.

Mission San Luis Rey and it’s surrounding lands became a large Mexican land grant following secularization, and the City of Oceanside was founded in the 1880’s to coincide with the arrival of the railroad between San Bernardino and San Diego.

Much of the original land grant property was sold to the United States government in 1942 for the establishment of Camp Joseph H. Pendleton Marine Corps Base. Oceanside has prospered ever since, with the influx of military, along with agriculture and tourism.