People moving through this landscape were not moving through emptiness.

They were moving through a known world — a world mapped in memory and transmitted through generations as knowledge of where reliable water could be found, where particular plant foods peaked in productivity in different seasons, where game animals could be reliably intercepted, and where shelter could be found against the cold and wind.

The Paisley Caves would have been a known location in this mental landscape — a south-facing shelter above a lake, reliably present, reliably sheltered, reliably close to water.

People who knew the landscape well would have known about these caves and returned to them.