I hadn't heard that 858.4875 had been labeled "Tan." This frequency is used for law enforcement only at Folsom and the Auburn State Recreation Area as I understand it. I show repeaters at:
Green Valley
Pilot Hill
Sore Finger Point
Blue is also used at the Auburn SRA, Folsom Lake, and Marshall Gold Discovery State Historic Park, all in the Gold Fields District. Orange is used at Empire Mine State Historic Park, as well as most of the park units in the Sierra Gold Sector of the Sierra District. Those units being Empire Mine, Malakoff Diggins, Plumas-Eureka, and South Yuba. Repeaters on Orange are Banner Mtn., Nulaid Ranch, Columbia Radio Site, and Backbone Ridge.
The Sierra and Gold Fields Districts are dispatched by "Northern" in Rancho Cordova. Northern used to be located near Folsom Lake but moved to Rancho Cordova some years back.
I just completed a major research project on California State Parks late last winter. I never wrote it up in a submission due to a lack of time. I'm even more pressed for time now, so I don't know when I can accomplish it.