Here's one I've been hearing since the early 1950's when my old uncle Charlie (God rest is soul) told me about a narrow gauge engine lost in the woods (stream?) in the Santa Cruz mountains in the Coast Range of California. The surrounding area is heavily populated (San Jose)but no one has found that engine nor has photographs of it. Forty plus some years later, my rail fan buddies in the bay Area reiterate the tale. What wheel arrangement that NG engine is-- no one can tell me. Sounds like a research project for Mulder and Skully.
Now how about the Rogers 4-4-0 + tank car and the 2-6-0 in the desert west of the Colorado River in Baja California! Those are the ones I want to go after.
regards
pat in Phoenix