dam has vastly reduced the amount of sediment in the Sacramento, and the riverbanks now suffer decreased erosion, slowing the growth of meanders and side-channels. Additionally, nearly all the rock and sand used in the mixing of concrete for the dam was dredged from the river downstream of the dam, further depleting its sediment supply. Wintu lands Underneath the waters of Shasta Lake lie buried the traditional lands of the Winnemem Wintu, one of nine groups of the larger Wintu ethnicity of northern California. The Winnemem Wintu tribe is considered to be a ghost tribe because they are not a federally recognized tribe. It is estimated that the pre-colonization population of the valley was roughly 14,000; by 1900, due to diseases and settlers' encroachment it was reduced to 395. Of the men who survived out of the 395, many fought in the U.S. armed forces during World War II. When they returned in 1945, they found their family members driven out of their traditional villages by the rising waters of Shasta Lake. More than 90 percent of their original land was lost, and the ten percent that remains now lies along the lower McCloud River. On May 1 of 1941, the United States Congress passed the Central Valley Project Indian Lands Acquisition Act, to take ownership of the homes and lands of the Winnemem Wintu people. Scores of village sites, burial sites and other sacred locations now sit several hundred feet below the surface of Shasta Lake. Over 27 sacred sites lie underneath the water behind the dam. Tribal members argue that several reservation treaties originally set by the U.S. government in the 1850s were later broken so the filling of Shasta Lake could proceed; afterwards, only a tiny fraction of that land remained theirs. Furthermore, the Winnemem are not recognized by the federal government, an omission that they have been seeking to rectify for over a century. Recently, native hostility to the dam has heightened because of the proposals to raise it – which would drown twenty of the remaining sacred sites, including Children's Rock and Puberty Rock, both used in coming-of-age ceremonies, and a burial place for victims of the Kabyai Creek Massacre. The tribe conducted a war dance in September 2004 for the first time in 117 years in opposition of the dam and Reclamation's raising project; the event reputedly inspired many environmental groups to support the