An artist unveils his mural of "Custer's Last Thought" at the local Western art museum.
In the foreground, a beautiful crystalline blue lake with a single fish leaping. Around the fish's head is a halo. In the background, the hills and meadows are covered with naked Native American couples copulating.
The curator is very angry and asks, "What the hell has this got to do with 'Custer's Last Thought?'"
The artist replies, "It's simple. Custer's last thought must have been 'Holy Mackerel! Where did all these fucking Indians come from?'"