to Pit 3 Powerhouse, located on the upper end of Pit 4 Reservoir, formed by Pit 4 Dam. Pit 4 is a much smaller diversion dam, drawing water through a tunnel under Chalk Mountain to Pit 4 Powerhouse on Pit 5 Reservoir. Like Pit 4, Pit 5 is also a small diversion dam with minimal pondage. From here, the water is diverted to an offstream regulating reservoir (Tunnel Reservoir) and then through a tunnel bypassing the Pit River reach known as the "Big Bend" and the eponymous town of Big Bend, to feed Pit 5 Powerhouse. These dams and powerhouses are licensed under the Federal Energy Regulatory Commission as the "Pit 3, 4, and 5 Project", and are operated by Pacific Gas and Electric Company (PG&E) Below Pit 5 Powerhouse lie two larger concrete arch-gravity dams, Pit 6 and Pit 7. These dams release water directly from the base to generate power, rather than diverting the water through long tunnels. The combined reservoirs flood almost of the Pit River. Flows for these two dams are supplemented by a diversion from the McCloud River, a tributary of the Pit River. Water is diverted from the McCloud River at Lake McCloud about south of Mount Shasta, through a tunnel to Iron Canyon Reservoir, and then through another tunnel to the James B. Black Powerhouse, which outlets into the Pit River on the upper end of Pit 6 Reservoir. These facilities are collectively known as the McCloud-Pit Hydroelectric Project and are also operated by PG&E. The lowermost of the Pit River are flooded by Shasta Lake, which is formed by Shasta Dam on the Sacramento River about below what was formerly the confluence of the Pit and Sacramento Rivers. Completed in 1945, Shasta is a key component of the U.S. Bureau of Reclamation's Central Valley Project, a primary source of irrigation water in the Central Valley. The lake also floods parts of two Pit River tributaries, the McCloud River and Squaw Creek. There are also multiple hydroelectric schemes on the Pit River's tributaries, such as the Fall River and Hat Creek. The Hat Creek Hydroelectric Project, which consists of two powerhouses on lower Hat Creek built in the early 1920s by Red River Lumber Co., is considered eligible for listing on the National Register of Historic Places. The Hat Creek facilities were purchased by PG&E in 1945. Before environmental regulations enacted in the