Greg, yes Tuolumne was the base for the Westside, not far from Sonora and Jamestown. Tuolumne was the end of the line for the Sierra Railway which hauled the outbound milled lumber from the WSL mill.
I'm not any kind of Westside expert since it lasted only a year after I "discovered" it. I think at the end they had seven ng. shays in operation, plus the one heisler that had been converted to sg. gauge to switch the mill. At one time they had about 70 miles of ng. "mainline" and 250 miles of logging spurs. However it twisted and turned so much that the 70 miles of mainline never got more than 18 miles from Tuolumne as the crow flies! At the end they were hauling logs about 40 miles from a reload near Clavey Bridge.
After WSL shut down a few miles of the line were operated as a tourist railway with a couple of the shays.
John