San Mateo (Crystal Springs) Dam, a concrete curved gravity structure built to provide San Francisco with water

Illustration showing horse-drawn carriages crossing the top of the dam with the reservoir on the left and the downstream face on the right.

Caption continues: As shown in this 1895 photograph, the San Mateo Dam featured a massive design similar to major municipal dams in the eastern United States and Europe. (Division of Engineering and Industry, National Museum of American History).
Illus. in: Building the ultimate dam : John S. Eastwood and the control of water in the West / Donald C. Jackson. Lawrence, Kansas : University Press of Kansas, c1995, p. 38.