Extended Ventura Co. into the Pacific Ocean

Extended Santa Barbara Co. into the Pacific Ocean

Extended San Luis Obispo Co. into the Pacific Ocean

Extended Monterey Co. into the Pacific Ocean

Extended Branciforte/Santa Cruz Co. into the Pacific Ocean

Extended Del Norte Co. into the Pacific Ocean

Extended Klamath Co. into the Pacific Ocean

Extended Humboldt Co. into the Pacific Ocean

Extended Trinity Co. into the Pacific Ocean

Extended Mendocino Co. into the Pacific Ocean

Extended San Mateo Co. into the Pacific Ocean

Extended Solano Co., Mare Is. non-county area into San Francisco Bay

Extended Sonoma Co. into San Francisco Bay

Removed stray county boundary member

Extended Marin Co. into San Francisco Bay

Extended Alameda, Contra Costa counties out into San Francisco Bay

Extended Alameda, Santa Clara counties out into San Francisco Bay (but not their townships)

Fixed date syntax

Fixed gaps in boundary relations

Alviso Twp. was created after 1851; Washington Twp. was expanded to embrace Alviso, not Alviso Twp. in May 1850