Actually, several 2-6-2Ts have been used in California, both NG and SG. Quincy RR 2 survives in Niles Canyon, operable, and Central Pacific 223 is resting unrestored at CSRM. Central Pacific, Southern Pacific, Tidewater Southern, Howard Terminal and I think California Western used 2-6-2Ts in SG.
Could the Kaiser line be related to the Eagle Mountain mine or the Steel Mill at Fontana? I thought those were too new for steam, but I may be wrong. Kaiser had/has several gravel/sand operations, but the ones I am aware of are in NorCal. Anything down south?