150 years ago, two cowboys come upon a Native American lying on his stomach with his ear to the ground.
One of the cowboys stops and says to the other, "You see that Injun?"
"Yeah," says the other cowboy.
"Look," says the first one, "he's listening to the ground. He can hear things for miles in any direction."
Just then the Native American looks up.
"Covered wagon," he says, "about two miles away. Have two horses, one brown, one white. Man, woman, child, household effects in wagon."
"Incredible!" says the cowboy to his friend. "This Indian knows how far away they are, how many horses, what color they are, who is in the wagon, and what is in the wagon! Remarkable! How do you do it?!?"
The Native looks up weakly and says, "Ran over me about a half hour ago."