Vintage Color Postcard Postcard. Identified as a scene on Blair Street in Silverton, Colorado. Here the two D. & R.G. Narrow Gauge trains await the return of their passengers for the trip back to Durango. Published by Petley Studios. Divided back, unused. Condition: This is an original photo postcard, not a copy or reproduction. It is in near mint condition. Comments: The town of Silverton is a Statutory Town that is the county seat of, and the only incorporated municipality in, San Juan County, Colorado, United States. Silverton is a former silver mining camp, most of which is now included in a federally designated National Historic Landmark District, the Silverton Historic District. The town population reached 637 in the U.S. Census 2010.