Editing Northern California (section)

==== Spanish era ====
The first European inhabitants were Spanish missionaries, who built [[Spanish missions in California|missions]] along the California coast. The mission at [[Mission San Carlos Borromeo de Carmelo|Monterey]] was first established in 1770, and at [[Mission San Francisco de Asís|San Francisco]] in 1776. In all, ten missions stretched along the coast from [[Sonoma, California|Sonoma]] to Monterey (and still more missions to the southern tip of [[Baja California]]). In 1786, the [[France|French]] signaled their interest in the northern California area by sending a voyage of exploration to Monterey.

The first twenty years of the 19th century continued the colonization of the northern California coast by Spain. By 1820, Spanish influence extended inland approximately 25 to {{convert|50|mi|km|0}} from the missions. Outside of this zone, perhaps 200,000 to 250,000 Native Americans continued to lead traditional lives. The [[Adams-Onís Treaty]], signed in 1819 between Spain and the young United States, set the northern boundary of the Spanish claims at the 42nd parallel, effectively creating today's northern boundary of northern California.