The film
Crafty railroad worker Bart becomes the first Black sheriff of Rock Ridge, a frontier town about to be destroyed in order to make way for a new railroad. Initially, the citizens of Rock Ridge harbor a racial bias toward their new protector. However, they warm to him after realizing that Bart and his perpetually drunk gunfighter friend Jim are their only defense against a wave of thugs sent to rid the town of its population.
Synopsis from TMDB.
The name
Also in Blazing Saddles