P-12-200-4160NA Klamath Project - Oregon-California. View of walkway installation at 36" CMP input, Sta. 51+90, left. Laborer using an earth wacker to drive sheet piling. Method seems to work but driver is a little light. Also, rock was encountered which caused some problems in driving the piling; May 1976; USBR photo by D. W. Stein