Interesting thread. I mostly lurk on the cryptid stuff and come from a BEK background but the geographic clustering angle is something I find genuinely compelling regardless of what the phenomenon actually is.
The railroad correlation keeps coming up in multiple cases and I dont think its just confirmation bias at this point. Old rail lines cut through specific terrain, follow water sources, run through old growth areas that haven't been developed - theres a lot of mundane reasons a large animal might follow them as corridors. But the clustering feels tighter than that in some reports.
What I'd want to know is whether anyone has actually mapped this properly against historical rail routes vs active ones. Because if abandoned lines show higher report density that tells you something different than active ones does. Anyone done that work or is it still just anecdotal pattern recognition at this stage?