This is by Bill Strider and it was published a few years ago on the groaners listserv.

Two park rangers are making their rounds in the Rockies when they discover a guy named Nathan erecting an oil rig on the side of a mountain. He explains that he has been inspired by those ads on the radio, and has decided to drill for beer. The rangers are going to issue a citation, but decide to do something crueler: let him try. Winking to his partner, one ranger observes that since the mountain won’t really be injured, “Why don’t we just let Nate, here, take its Coors?”