Formerly swampland, it was reclaimed into productive farmland, and became the subject of lengthy legal disputes in the early 20th century.

[5][4] The entire cluster of islands is west of the Napa River, near where it empties into San Pablo Bay, across which is the city of Vallejo.

Many of the islands at the mouth of the Napa River were first discovered by Europeans in an 1823 Spanish expedition led by Francisco Castro.

The area is not charted in surveys of that time, including Cadwalader Ringgold's 1852 map of San Pablo Bay.

[9] Later, it came into the possession of David T. Hanbury, an "English scion" and millionaire who owned several breweries and wineries in England and California.

[10] On October 21, 1908, the island was deeded to David's wife Marie Eleanor Hanbury, a "former Benicia hello girl".

2 was executed by Marie "with the utmost secrecy"; David was unable to sign the document "owing to illness".

[10] The Weekly Journal hypothesized that the mortgage had been executed in order to pay the Hanburys' debts in Vallejo.

[11] This deed had been executed in San Francisco on January 8, 1908; it was, however, entered into the county record nearly a month after the transfer of the island to Marie.

[13] David engaged an attorney, Hiram Johnson, to "establish the validity of [his] wife's deed to the property".

[14] By 1910, divorce proceedings between David T. Hanbury and Marie Eleanor were underway; the Napa Weekly Journal said that during these proceedings "the title to the famous island passed rapidly from Hanbury to his wife, then to his brother John, the English brewer, and again to the Napa Bank, and all around the circle again".

[15][14] David T. Hanbury died in October 1910, at the White Sulphur Springs in Solano County, having gone there for treatment of his poor health.

[17] A December 1915 announcement in the San Francisco Recorder mentioned an "undivided three-fourths interest in all of Island Number Two".

[18] In 1916, W. L. Williamson and F. Henritty were arrested on charges of disturbing the peace, after a "quarrel over a lease on Island No.

William Banta, David Mackenzie's uncle and legal guardian, was sued by the British members of the family for ownership of Island No.

2 became part of the Napa-Sonoma Marshes Wildlife Area, as a "managed pond" administered by the California Department of Fish and Game.