Looking at Santa Rosa historical quad maps, it appears that both the NWP and SP lines through the Sonoma Valley were mostly gone by the 1950s if not WW2. The SP line remained as a spur into the 1960s, from the wye near Jennings Ave. through Santa Rosa JC then a r/w parallel to Pacific Ave. then curving to parallel the east side of what is now North Street to end amid warehouses short of College Ave. Most of the tracks were gone by the time I lived there 1973-77, but had not been gone for long (the railroad crossing of Mendocino Ave. still had a patch rather than new pavement - the full repave came later). From there, Brookwood Ave. and Montgomery Dr. are where the SP tracks ran (I don't know where, or if, NWP ever made it all the way to SR; mapped things and visible remnants kind of peter out around Glen Ellen). The entrance road to Annadel state park now runs along the old RR line. Parts of it are still visible elsewhere in the Sonoma Valley, too.

Location of the line can still be seen in the property lines shown by the Google Map of this part of the "Junior College" neighborhood. [www.google.com]

As for El Verano, I remember being dragged along as a kid to church picnics and other parties at "Little Switzerland" on Grove St. Not much of the place left - just the main restaurant building (big parties were in a space across the street along the creek).