Jersey Island

Marsh Creek is a stream in east Contra Costa County, California in Northern California which rises on the eastern side of Mount Diablo and flows 30 miles (48 km) to the Sacramento–San Joaquin River Delta at Oakley, California, near Big Break Regional Shoreline. The creek flows through Marsh Creek State Park (California), where water is impounded to form Marsh Creek Reservoir, then through the city of Brentwood, California.

{{Merger with Franks Tract State Recreation Area has been proposed. Please see Talk page.}} The Antioch Bombing Target a 500-acre (200 ha) plot was a United States Navy target used from 1943 to 1952. It is now part of the Franks Tract State Recreation Area.

Bethel Island is an island in the Sacramento–San Joaquin River Delta of Contra Costa County, California, approximately 10 kilometres (6.2 mi) east of Antioch. The island describes itself as "the heart of the California Delta." Bethel Island (formerly known as Bethell, Bethell Ranch, Bethel Tract, Sand Mound Ranch, Sand Mound Tract) is also a census-designated place (CDP) on the island. The population at the 2010 census was 2,137, a 7.6 percent decline from 2,312 at the 2000 census. The community of Bethel Island is governed as a Special Act District created by the California State legislature and named the Bethel Island Municipal Improvement District (BIMID). It is a popular destination for recreation seekers, especially hunters, fishermen and boaters.

Bradford Island is a 2,172-acre (879 ha) island of the Sacramento–San Joaquin River Delta, in Contra Costa County, California, United States. Bradford Island is inaccessible by roads, and is served by a ferry across the False River from nearby Jersey Island. Approximately 48 people lived on the island as of 2020; other uses of land include wheat farming, cattle grazing, and natural gas extraction. Bradford Island is a reclaimed peat wetland; as it lies below sea level, it is protected by flooding by levees. These, as well as a pump station and internal drainage canals, are administered by Reclamation District 2059, founded in 1921. The levees have been breached on several occasions, leading to the island becoming flooded. Bradford Island is one of eight Delta islands considered critical to the region's water quality by the California Department of Water Resources.

Oakley station is a planned station that will be a stop on Amtrak California's San Joaquin service. It is located near Main Street between O'Hara Avenue and 2nd Street. The station was partially funded by a 2018 grant from California's Transit and Intercity Rail Capital Program. Construction was expected to be completed by 2022. As of March 2023, the station is expected to open in the third quarter of 2024, replacing Antioch–Pittsburg station.

Oakley is a city in Contra Costa County, California, United States. It is within the nine-county San Francisco Bay Area. The population at the 2020 United States census was 43,357. Oakley was incorporated in 1999, making it the newest incorporated city in Contra Costa County.

Franks Tract State Recreation Area (SRA) is a state park unit of California, United States, featuring a flooded area in the Sacramento–San Joaquin River Delta. It is accessible only by water. Franks Tract, and a smaller adjoining submerged property called "Little Franks Tract", are situated between the False River and Bethel Island. The recreation area is used primarily for fishing and waterfowl hunting, because of its exposure to frequent strong winds and fluctuating water levels. In times of high water, the entire site can be submerged except for portions of the old levees. The 3,523-acre (1,426 ha) park was established in 1959. It is managed from nearby Brannan Island State Recreation Area, 6 miles (9.7 km) to the northwest.

Big Break Regional Shoreline is a regional park in Oakley, Contra Costa County, northern California. It is a part of the East Bay Regional Park District system.

Sherman Island is an island in the Sacramento-San Joaquin River Delta at the confluence of the two rivers in Sacramento County, California, 1.2 miles (1.9 km) northeast of Antioch. The 5,500 ha (14,000 acres) island, mostly managed by Reclamation District 341, is the meeting point of Sacramento, Solano, and Contra Costa Counties, and is bordered on the north and northwest by the Sacramento River, on the northeast by Three Mile Slough, and on the east, and south west by the San Joaquin River. Sherman Island is a widely known kite and windsurfing area. Sherman Island was shown, in the same location but with a different shape, on an 1850 survey map of the San Francisco Bay area made by Cadwalader Ringgold and an 1854 map of the area by Henry Lange. Currently, it is 10 feet below sea level, due to the drainage of wetlands in the Delta which has dried out its peat soils, resulting in land subsidence. "In ... parts of Sherman Island, the land has now subsided 25 feet since the late 1800s—and continues to sink between half an inch and 1.5 inches yearly." It is possible that simultaneous levee failures on Sherman Island and surrounding islands, occurring in the wake of an earthquake, could threaten the fresh water supply for the Central Valley.

The Contra Costa Canal is a 47 mi (76 km) aqueduct in the US state of California. Its construction began in 1937, with delayed completion until 1948 due to World War II shortages in labor and materials. A portion of the canal's right of way has been developed as the Contra Costa Canal Regional Trail, a biking and walking trail, and is managed by the East Bay Regional Park District.