I found a Mud Volcano in California

Fun fact! If you drive around SF you'll occasionally see little brick circles in the road. They're underground water cisterns that were put there after several fires in the 1850's. In 1906 the quake disrupted the ability to transport water around the city, which is one of the reasons the fires lasted for so long. Luckily they were able to use the cisterns to help fight the fires, and the city has been maintaining them ever since (even adding new ones on occasion).