Hideout Saloon
Updated:
Walk one block down from the main street of Mariposa, go through a nondescript gate and follow the path to the basement of one of the houses - and you'll end up at the Hideout Saloon.
The walls and ceiling are covered in bills, and visitors may nail one to any empty spot. The back wall is a supply of coins - in case you've spent all your gold and need to borrow a quarter for your next beer.