Search for maps - Dutch Flat Wagon Road

From: Edward L Hodges ehodges@ix.netcom.com

Five of my history buff friends visited the State Archives last month and viewed about 15 maps including the 100' Judah map showing in extreme detail the route of the RR over the summit. We also paid a visit to the RR Museum Library in Old Town and found some interesting maps showing CPRR stations in great detail. I was personally looking for more info. on the Dutch Flat Wagon Road. Specifically, I am looking for survey maps that might have been created in 1863-64. I know that R.H. Pratt was the general superintendent of road construction (see my attachments), and I suspect that maps were created because the road was closely associated with the RR.
Do you have suggestion on where I might look?
As I await your reply, I remain sincerely,

Ed Hodges, San Jose