In the '50s coal for the Kaiser steel mill at Fontana came across Cajon Pass in MoPac hoppers, though I don't know where it came from. The Kaiser mill was the only So. Calif. recipient of coal in significant amounts.
Nearly all this coal was western Colorado/eastern Utah coal. There are photos of both Utah Coal Route gons, and D&RGW gons and hoppers, at Kaiser. Given the historic connections and cooperation between Mopac and the Rio Grande, one can imagine some car sharing. Tony Thompson
While it's true that much Fontana coal and ore came from Utah, I have not seen photos of MP hoppers on the Rio Grande or UP in that area. I think it's idle speculation in the absence of photos.
