I think that Earl is correct that Mineral St is about right for today's track for MP 497. The 497 post lasted well into the 70s when it disappeared. The End of Track sign is very heavy and I think well anchored so it survives. The routing of Cement Creek has changed since Dick's map, and I believe that some of that was done as recently as the 1970s so that Cement Creek is further north. The course of the creek as shown on Dick's map would interfer with the current 12th Street alignment, so perhaps the D&RGW did creek work in the 50s, and then in the 70s, the LP gas plant took it on themselves to further change the creek to regain some of their land that was under water. Most of this can still be traced on the ground, but check it out soon as the powers that be in town are hell bent for making improvements, like hiking trails and affordable housing that is wiping out a lot of the remaining rail landmarks.
Fritz