Archaeologists have found cog stones as the site is believed to have been the home some 9,500 years ago for the Acjachemen and Tongva tribes.

[3] Speculation has centered on religious or astronomical use of the stones which have been included in collection of the Bowers Museum in Santa Ana.

Once Spain colonized California, Spanish officials created vast land grants called ranchos.

Prior to 1899, there had been a natural ocean entrance to the wetlands where the East Garden Grove Wintersburg Channel, then a small stream, is now located.

[4] In 1899, the Bolsa Chica Gun Club was formed by a group of wealthy businessmen from Los Angeles and Pasadena.

The ceiling was constructed with 16 feet of solid concrete capable of withstanding a direct hit from naval and air attacks.

In the 1960s, most of Bolsa Chica was acquired by Signal Landmark, and plans for a massive housing development and marina were released.

State officials objected, and so in 1970 the developer set aside 300 acres (1.2 km2) alongside Pacific Coast Highway to create the Bolsa Chica Ecological Reserve.

[7] In 1990, the Amigos and the developer, now called Hearthside Homes, entered a joint agreement to create the Bolsa Chica Conservancy.

Restoration was completed in 2006 at a cost of $147 million which included opening an inlet to the Pacific Ocean for the first time since being dammed in 1899.

The developer contributed to the campaign of bond measure Proposition 50, which included specific language to purchase land at Bolsa Chica.

Proposition 50 passed, and the state ended up purchasing 118 acres (0.48 km2) of the lower bench, closing escrow in December 2005.

Beginning in December 2007, flood control improvements were made by the County of Orange to reinforce the levees damaged in the rains of 2005 and protect the wetlands.

Highlights of their community programming include: Among the wildlife in the reserve are the shovelnose guitarfish,[15] grey smooth-hound sharks,[15] California halibut,[16] and white seabass.

[citation needed] Other wildlife include western fence lizard, cottontail rabbit, Beechey ground squirrel, and coyotes.

[18] Bird species at the reserve include the endangered light-footed rail,[19] snowy plover, Savannah sparrow, least tern, Caspian tern, great blue heron, snowy egret, double-crested cormorant, red-tailed hawk, great horned owl, and California gnatcatcher.