Martinez, California

Martinez (Spanish: Martínez) is a city in and the county seat of Contra Costa County, California, United States, in the East Bay region of the San Francisco Bay Area. Located on the southern shore of the Carquinez Strait, the city's population was 37,287 at the 2020 census. The city is named after Californio ranchero Ygnacio Martínez, having been founded on his Rancho El Pinole. Martinez is known for its historic center and its waterfront.

The beautiful, lush Alhambra Valley was probably a seasonal foraging “pantry” for the stable population of the Karkines Indians. The Karkines are a part of the Ohlone (Costanoan) Indian group.

In 1824, the western side of Martinez, Alhambra Valley was included in the Rancho El Pinole Mexican land grant to Ygnacio Martínez. East of these lands was the Rancho Las Juntas, a grant made to Irish born William Welch in 1844; his land lay between the lands of Martinez and Pacheco.

In 1847, Dr. Robert Semple contracted to provide ferry service from Martinez to Benicia, which for many years was the only crossing on the Carquinez Strait. By 1849, Martínez served as a way station for the California Gold Rush. The town was laid out in 1849 by Col. William M. Smith and named for Martinez. It became the county seat in 1850, but could not incorporate at the time because it lacked the 200 registered voters required, and would not become a city until 1876.

Martinez was the home of naturalist John Muir from 1880 until his death in 1914. He was buried about a mile south of the building that is now the John Muir National Historic Site. Also nearby is the Vicente Martinez Adobe, built in 1849 by the son of Ygnacio Martinez.

The first post office opened in 1851.

In 1860, Martinez played a role in the Pony Express, where riders would take the ferry from Benicia (particularly if they missed the steamer in Sacramento).

The first oil refinery in the Martinez area was built in 1904 at Bull's Head Point, a then-unincorporated waterfront area two miles east of the downtown district. That area soon became known as Mococo, following the 1905 arrival of a smelting works, operated by the Mountain Copper Company (Mo Co Co).