In this photo taken Thursday, Dec. 13, 2012, Matt Collins, chief operating officer of the Sutter Gold Mining Co., left, watches as Allen Smith, second from left, Brain Herfel, third from left, Ted Chapman fouth from left, and Wayne Murphy, right, calibrate the water flow of a gravity table at the company's newly constructed mill near Sutter Creek, Calif. The gravity table uses technology similar to those used by gold rush-era miners who used pans to separate gold from surrounding materials. The company, which has begun mining adjacent to the historic Comet-Lincoln ore zones, announced Monday, Dec. 17, 2012, that it poured its first gold as it prepared to begin the first large scale Sierra Nevada underground gold mining in a half century. (AP Photo/Rich Pedroncelli)

Associated Press
In this photo taken Thursday, Dec. 13, 2012, Matt Collins, chief operating officer of the Sutter Gold Mining Co., left, watches as Allen Smith, second from left, Brain Herfel, third  from left, Ted Chapman fouth from left, and Wayne Murphy, right,  calibrate the water flow of a gravity table at the company's newly constructed mill near Sutter Creek, Calif. The gravity table uses technology  similar to those used by gold rush-era miners who used pans to separate gold from surrounding materials.    The company, which has begun mining adjacent to the historic Comet-Lincoln ore zones,  announced Monday, Dec. 17, 2012, that it poured its first gold as it prepared to begin the first large scale Sierra Nevada underground  gold mining in a half century. (AP Photo/Rich Pedroncelli)
In this photo taken Thursday, Dec. 13, 2012, Matt Collins, chief operating officer of the Sutter Gold Mining Co., left, watches as Allen Smith, second from left, Brain Herfel, third from left, Ted Chapman fouth from left, and Wayne Murphy, right, calibrate the water flow of a gravity table at the company's newly constructed mill near Sutter Creek, Calif. The gravity table uses technology similar to those used by gold rush-era miners who used pans to separate gold from surrounding materials. The company, which has begun mining adjacent to the historic Comet-Lincoln ore zones, announced Monday, Dec. 17, 2012, that it poured its first gold as it prepared to begin the first large scale Sierra Nevada underground gold mining in a half century. (AP Photo/Rich Pedroncelli)