Placer gold first attracted adventurers to the northern mines after its discovery in Shasta County in 1848, but almost immediately, valuable deposits of copper were also noted. Copper production remained idle until the Mountain Copper Company acquired Iron Mountain in 1896. British and eastern financiers such as Guggenheim and Rothschild saw the potential in the unique combination of high-grade copper ore, a functioning railway, and vast quantities of limestone and quartz for flux, and they invested in major smelters to conquer the difficult sulfide ore. The decades that followed were the greatest period of prosperity in Shasta County's history, producing towns such as Coram, Keswick, Kennett, and Copper City and attracting thousands of hardworking miners and townspeople as well as new railroads such as the Sacramento Valley & Eastern, Quartz Hill, and Iron Mountain. While the boom ended in deforestation and erosion, the actions of the Bureau of Reclamation and the Shasta Dam brought prosperity to the area. Today, most of the copper towns rest under Lake Shasta.