From California Historical Landmarks
Here, on Christmas Day, 1846, natives and soldiers from the Presidio of Santa Barbara lay in ambush for Lieutenant Colonel John C. Frémont, U.S.A., and his battalion. Frémont learned of the plot and, guided by Benjamin Foxen and his son William, came instead over the San Marcos Pass, to capture Santa Barbara without bloodshed.
The Santa Barbara Independent has an interesting article about Benjamin Foxen and whether he helped Frémont avoid the ambush.
Location and Vicinity Map