Where are the few confirmed Minnesota records of the Western Ratsnake concentrated?

Paleozoic Plateau Section, specifically on wooded bluffs

The limited records for the Western Ratsnake in the northern extremes of its range, specifically in Minnesota, reveal a strong dependency on particular geological and topographical features. Unlike the more adaptable central populations, the confirmed sightings in southeastern Minnesota are strictly concentrated within the geological structure known as the Paleozoic Plateau Section. Within this section, the snakes are found exclusively on wooded bluffs. This geographical restriction suggests that, for populations surviving at the colder edge of their tolerance, the availability of these high-quality, climatically buffered sites—like bluffs offering suitable features for denning—is essential for persistence.