Listen to this Gambling History blog post here
A wild burro sauntered into the popular gambling spot, the El Rey Club in Searchlight, Nevada at about 11 o’clock every morning. It approached the proprietor, Willie Martello, who always fed it something he had in his pocket. Then the donkey retreated back into the desert.
Photo from freeimages.com: “The key is the donkey,” by dimitri_c