Janet is right. Northern California suffers from a relative dearth of brick buildings. Why? Earthquakes. Brick buildings tend not to stand up to earthquakes too well. In the big 1906 quake, Santa Rosa suffered proportionally more damage than San Francisco. Practically every brick edifice in town collapsed. Nowadays, most of the brick walls around here are facades of buildings constructed with steel beams.
But bricks can definitely be found, which proved important for the monthly Challenge.