Stevenson's Silverado stay was in Napa County. He also did time in San
Francisco (which is its own city and county) and Monterey which is in
Monterey county. And on his way to his honeymoon stay at the mine in
Silverado he stopped for a night in Vallejo (Solano County) and described it
in most unpleasant terms.
I am sure that the county librarians for Marin and Sonoma would be courteous
and helpful, but Stevenson might not be their area of special interest.
Dennis Kelly