Martinez (Spanish: Martínez) is a city and the county seat of Contra Costa County, California, United States. The population was 35,824 at the 2010 census. The downtown is notable for its large number of preserved old buildings and antique shops. Martinez is located on the south side of the Carquinez Strait in the San Francisco Bay Area, directly facing the city of Benicia.
In 1824 the Alhambra Valley was included in the Rancho El Pinole Mexican land grant to Ygnacio Martínez. 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 only became a city in 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). In 1915, Shell Oil Company built an oil refinery in unincorporated Martinez, which sparked a building boom in the area. A second area refinery (presently owned by Tesoro Petroleum Co.), together with the Shell facilities, help make Martinez a significant petroleum processing center and port. The oil refineries in and near Martinez can still be seen today from Interstate 680.
Folk etymology in Martinez claims the invention of the Martini cocktail and that it is named for the city.
According to the United States Census Bureau, the city has a total area of 13.1 square miles (34 km2), of which, 12.1 square miles (31 km2) of it is land and 1.0 square mile (2.6 km2) of it (7.64 percent) is water.
Although the common perception of Martinez is that of a refinery town, given the view from Highway 680 across the Shell refinery from the Benicia–Martinez Bridge, the city is in fact largely surrounded by water and regional open space preserves. The Martinez–Benicia Bridge carries Highway 680 across the eastern end of the Carquinez Strait to Solano County. The city can be defined as a more densely built downtown valley threaded by Alhambra creek and north of Highway 4. Suburban areas stretch south of Highway 4 to join the neighboring city of Pleasant Hill. Unincorporated areas include the rural Alhambra Valley and the Franklin Canyon area.
The Martinez Regional Shoreline bounds the city to the north along the Carquinez Strait. Carquinez Strait Regional Shoreline includes the Franklin Hills west of downtown, stretching west to the unincorporated community of Port Costa and the town of Crockett. Briones Regional Park borders the Alhambra Valley to the south. Waterbird Regional Preserve and the McNabney Marsh border the city and Highway 680 to the east. Martinez’s location at the east end of the Carquinez Strait as it widens to Suisun Bay includes dramatic water views stretching to the Sierra range. From surrounding ridge tops views stretch to nearby Mt. Diablo, Mt. St. Helena, Mt. Tamalpais, etc.
Martinez is one of the only two places in the Bay Area, the other being Golden Gate Bridge, where the Bay Area Ridge Trail and the San Francisco Bay Trail converge. The Bay Trail is a planned recreational corridor that, when complete, will encircle San Francisco and San Pablo bays with a continuous 400-mile (640 km) network of bicycling and hiking trails. It will connect the shoreline of all nine Bay Area counties, link 47 cities, and cross the major toll bridges in the region, including the Benicia–Martinez Bridge. To date, approximately 240 miles (390 km) of the alignment—over half the Bay Trail’s ultimate length—have been completed. The Bay Area Ridge Trail ultimately will be a 500+ mile trail encircling the San Francisco Bay along the ridge tops, open to hikers, equestrians, mountain bicyclists, and outdoor enthusiasts of all types. So far, over 300 miles (480 km) of trail have been dedicated for use. East Bay Regional Park District’s Iron Horse Regional Trail will join the Bay Trail along the waterfront, and the Contra Costa Canal Trail threads through the city from Pleasant Hill to the south.