California Code, Government Code - GOV § 160

The line run and marked by the United States Government under the Act of June 10, 1872, 17 Stat. 358 (1872) from the southern boundary of the State of Oregon to the 39th degree of north latitude and the line established and marked by the United States coast and geodetic survey, as completed in 1900, extending southeastward from the intersection of the 39th degree of north latitude with the 120th degree of longitude west from Greenwich to the Colorado River comprise the legal eastern boundary line of the state from the Oregon boundary to the Colorado River, and shall be so considered by the courts of the state.