The Alta California Telegraph Company (also referred to simply as the Alta Telegraph Company) was a telegraph company which operated in the mid-19th century within the state of California prior to the construction of the Transcontinental Telegraph. It was organized in 1853, and incorporated in January 1854 and began constructing its first line that same year, stretching from Sacramento to Marysville and extending up into the foothills of the adjacent Sierra Nevada mountains. In subsequent years, a line was constructed between Sacramento and Benicia. From Benicia, a branch line was extended to Vallejo and the US Navy yard at Mare Island.