SAN MATEO


History and Map

San Mateo County was formed in 1856 after San Francisco County was split apart. In response to the lawlessness and vigilantism that escalated rapidly between 1855 and 1856, the California government decided to divide the county. A straight line was drawn across the tip of the San Francisco Peninsula just north of San Bruno Mountain. Everything south of the line became the new San Mateo County while everything north of the line became the new San Francisco County.

San Mateo County bears the Spanish name for Saint Matthew. As a place name, San Mateo appears as early as 1776 and several local geographic features were also designated San Mateo on early maps including variously: a settlement, an arroyo, a headland jutting into the Pacific (Point Montara), and a large land holding (Rancho San Mateo).


State Historical Landmarks