A childhood belief about road signs

While driving in our car, I asked my father what the "Falling Rock" signs meant. He went on to tell a story about an Indian boy who was sent out into the woods to retrieve an animal for food to prove his manhood. The boy never returned.
My father explained that whenever I see that sign it means there has been a sighting of the young Indian boy named Falling Rock.
The sad part is that I thought I saw him a couple of times. Hey, I was young, alright?