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." The population at the 2010 census was 2,137, a 7.6 percent decline from 2,312 at the 2000 census.
Bethel Island, which was named after the Bethell Brothers, Frank and Warren Bethell, who formed the first successful farm on the island, called Sand Mound Ranch. Frank Bethell was appointed postmaster of the first post office, however, a pious clerk at the U.S. Postal office did not want the name "Bet Hell" and dropped the additional "L" to make it "Bethel" Hebrew term בית אל beth el, which translates to "House of God," is known for its recreational activities. The island's reputation as such began in 1930, with Blanche and Jack Farrar founding a park with swimming, picnicking and other outdoor activities. This park would eventually be called Farrar Park. Remsburg Marina was started by Warren Remsburg in 1938, and in 1944 a fishing resort called Frank's had gained popularity on the island. The resort was built by the Andronico family. By the 1950s the area became popular with sport fishermen and the rich. Frank Bethell and Warren Bethell's widow, Ann Youree (Hamilton) Bethell sold their interest in the island in 1901. Ann went on to form a successful ranch in Almaden Valley and established the Bethell Block in downtown San Jose (site of the current Federal Building.
Bethel Island, California, is located in East Contra Costa County. It is one of the western islands within the California Delta region. The 1,450 ha (3,600-acre) island is bounded on the west and northwest by Taylor Slough, on the north and east by Piper Slough, on the southeast by Sand Mound Slough, on the east by Frank's Tract, and on the southwest by Dutch Slough. The island is approximately 3,500 acres (1,416 ha) in size.
The Bethel Island Municipal Improvement District (BIMID) has five directors, elected from the local community. They are responsible primarily for maintaining the levee around the island. They also have responsibilities for water supply and drainage; parks and playgrounds; and the local airports.