Coors Banquet beer was black market back in the day, only distributed within some 13 western U.S. states. Per firstwefeast.com, in the 1970’s:
Coors claimed that not only could they not make enough beer, but that their unpasteurized brew demanded being distributed exclusively via refrigerated trucks, lest it “spoil.” Thus, a mystique was built, and soon east coast folks were smuggling cases upon cases of the beer back home after a visit to the Rockies. In 1977, Coors even took out an ad in the Washington Post saying “Please don’t buy our beer,” insisting any in the area was clearly black market, mishandled, and prone to becoming “watery” (you can laugh now). This insane thirst for Coors hit its apex with the release of Smokey and the Bandit, the Burt Reynolds action-comedy about a legendary trucker willing to risk life, limb, and the law to illegally smuggle crates of Coors back to Georgia.
This ’79 ad for said beer plays like an ad for America itself. Coors Banquet is “born where eagles speak, and the sunrise slides from peak to peak.” Clearly, it’s “no downstream beer.”