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.