In Utah, a partition that separates the patrons of a bar from the bartender and prevents drinks from being passed directly from the place where they are mixed to the customer.
The name comes from "Zion," a reference to the LDS (Mormon ) Church whose prohibitions against drinking alcohol heavily influenced Utah's liquor laws.
Because the bar that she tended at had a Zion Curtain, Sarah had to walk around to the other side to hand every customer their drink. It was a pain in the ass, but at least it was good exercise.
The part of the western USA where the Church of Jesus Christ of Latter-Day Saints is most prevalent, especially the states of Utah, Idaho and Wyoming. Taken from the term "Iron Curtain" coined by Winston Church to describe the formerly communist Eastern European nations.
Though it's deep behind the Zion Curtain, Salt Lake City is a relatively progressive city.