Hi Mateusz, while the Stockton Mills Rail has been torn up decades ago, there are traces of that rail way that would have been there including railroad ties and smaller parts of the rail that have been cut up. Check out this image for an overall view: http://www.sbdepotmuseum.com/1850-1879/august-4-1852-sacramento-valley-railroad.html. I don't have a publicly accessible image of the original track. Since there is no official name to the rail system that had connected the Folsom Dam and prison to old Town Folsom, I used the landmark "Stockton Mills" which is where the railway pointed to in old Folsom. We can leave off the name if it is required it be official and set the tag as "name:absent=yes". 
