Jackson & Sharp supplied cars to the Denver South Park & Pacific, the Colorado Central when they were new. Then the Denver, Leadville & Gunnison acquired them when they bought the two railroads out and then the Union Pacific Denver Gulf followed suit after acquiring the DL&G and finally the Colorado & Southern used them until the end. I believe that the F&CC, the three Silverton Railroads, Eureka & Palisade, and Nevada Central may have used Jackson & Sharp cars from time to time. I cannot confirm them at this moment but others can chime in as well.
We have witnessed valley
and plain and crest,
Canon and pass we've scanned;
We have seen the best
of the glorious West,
by the trail of the Rio Grande
-Author Unknown