This article is from the Yolo County FAQ, by David F. Prenatt, Jr. with numerous contributions by others.
While the Age of Exploration and subsequent historical developments
took their toll upon all cultures in the New World, it had no special
or noteworthy impact upon the aboriginal inhabitants of Yolo County.
Early on, the Spanish Mission system came very close to Yolo County
with the founding of San Francisco de Asis in 1776. However, this
mission and other neighboring missions had little influence on the
life of aboriginal California residents outside of the San Francisco
Bay Area. By the time San Francisco Solano was founded in 1823 the
Mission System was no longer even a viable institution in California.