Mystery ties

A friend tells me about a stack of some partially-decayed railroad ties near the remains of Crossons, Colorado. Some of the ties still have spikes in them, with a tight 4” between them for the base of the rail. The inside distance between what would have been the bases of the rails is only 23 inches, making the rail gauge around 25 inches. Would anyone have an idea about the original use of these ties? This is along the roadbed area for what I’ve seen identified both as the Colorado & Southern Railway, and/or the Denver, South Park & Pacific. But weren’t those 3-foot gauge lines? Could these mystery ties have been from a mine tunnel railway, perhaps? Any help on this would be greatly appreciated!
Robert