There was common belief among Native Americans that spirits Animals underground, so, when game animals disappeared that is where they were to be found. Animals would enter and exit through the cracks or rocks. The feet and tracks on boulders create the impression of human and animals walking to the apex of the rock, beginning at ground level. Therefore the tracks seen on the Boulder may represent the animal and spirits coming back to our world.
Animal tracks carved into Track Rock boulder.
Plaque courtesy Lat34North.com.
Original page, with additional info, here.
Photo credit: Byron Hooks of Lat34North.com.