> But I bet cityfolk have a reeeeeeaally different notion of "road" than is meant here.

Yes, they mean : no throughfare usable by a regular vehicle including high clearance 4wd, including private roads, tracks etc.

In the Absoroka here there are "inholdings" (I think they're the remnants of old mining claims) that the owners access via helicopter. There have been a few court cases about access over the years e.g. https://www.bozemandailychronicle.com/lawsuit-seeks-to-build...