This 1926 cover shows a wooden stave pipe under construction in northern California. The 16-ft-dia, 1,318-ft-long conduit connected two concrete-lined tunnels at a hydroelectric plant on the Klamath River. It was seated on concrete footings that supported steel cradles holding the pipe, with steel T-bars over the top of the pipe and bolted to the cradles. The creosoted staves were 4 in. thick and 53⁄8 in. wide. When in service, the pipe would always be full and under pressure. Steel standpipes installed at each end of the line where the pipe entered the concrete tunnels were expected to prevent the occurrence of vacuum inside the pipe and allow any entrapped air to escape. The project’s owner was the California Oregon Power Co., and the Continental Pipe Manufacturing Co. of Seattle served as pipe contractor.