Haven't tracked dogman specifically but this lines up with something I've been noticing with Bigfoot reports in WV. A lot of the hotspots here follow old coal and timber rail routes. My theory is its less about the railroad itself and more about the corridor - old rail lines usually mean undisturbed tree cover on both sides for miles, water drainage running alongside, and minimal human traffic.
Basically perfect wildlife habitat threading through otherwise developed areas.
The railroad connection might just be a proxy for "isolated green corridor that nobody's walked in 40 years." Would be worth mapping the sightings against abandoned vs active lines to see if theres a pattern there. Anyone actually done that or is it all anecdotal so far?