The Silver Vista - D&RGW car 313 - was a narrow gauge observation gondola with a glass roof and open sides (though there were window shades that could be drawn during inclimate weather). This is the original, built by the Rio Grande's own Burnham shops in 1947 from outfit car #0313. It lasted a mere six years, destroyed by a fire at the Alamosa, CO, car shops on 30-Sep-1953.
In 2006, the Durango & Silverton recreated the Silver Vista with their own version of the car. For more of it, see [here].
Silver Vista on the back of a Silverton train during June 1953. No note on location, but looks to be either around Ah Wilderness or Tefft. I think that tree is still there, but I can't quite place it. Charles Franzen negative.