TODAY is National Moonshine Day, when American tipplers lift a mason jar to the illegal liquor that got them through Prohibition. For most drinkers, that world of bootleggers and secret stills is just a part of history. But roughly 18m Americans still live in “dry” counties or municipalities, where the sale of alcohol is banned by law. How have these holdouts survived into modern times, and what are the consequences for people who live there?

Parts of the United States were dry even before the start of Prohibition. Maine implemented its own anti-booze rules as early as the 1840s. In 1919, the 18th amendment spread these restrictions nationwide. While many Americans lamented the ban—and dodged it by getting legal whisky prescribed by doctors—others rejoiced. Some Protestants saw boozing as sinful, while others fretted about the social dangers of letting immigrants and the poor get drunk. These attitudes persisted even after 1933, when President Franklin D. Roosevelt switched on the taps again. Several states kept up their own prohibitions. Mississippi bars only reopened their doors in the 1960s. As late as 2006, South Carolinians visiting a local bar could only buy shots from tiny bottles better suited to an airliner’s drinks trolley.

Statewide bans on alcohol have now disappeared. But around 10% of the country, by area, keeps up local restrictions, especially in the South. As of late last year, six counties in Texas and 35 in Arkansas were still dry. Rules in parts of Alaska are so strict that the mere possession of alcohol is illegal. Even so-called “moist” counties only permit drinking in certain areas, or limit drinking in other ways (by restricting alcohol sales to large restaurants, for example). Though campaigners try to loosen rules—in 2016 Alabamians voted to abolish their last teetotal county—change can be slow. This is partly social. Americans might be more liberal than they were in 1919, but cautious attitudes remain. A culture of abstinence “has had a lasting residual impact” in some areas, explains one modern prohibitionist. Legal hurdles hardly help. Thirsty citizens in Arkansas can only get prohibition repeal on a ballot if 38% of voters in any given jurisdiction sign a petition, whereas other issues qualify for a referendum with just 15%. Some drinkers even sabotage repeal efforts themselves. Bootleggers in a dry corner of Alaska, worried their business would collapse, plied voters with free drink to persuade them to vote against going legally wet.

These desperate tactics are unsurprising: prohibition still offers space for unscrupulous vendors to get rich. At the Pine Ridge Indian Reservation, near South Dakota’s border with Nebraska, bootleggers sell beers for $3 and vodka (mixed with hand sanitiser) for $10. Prohibition can be dangerous in other ways, too. Because people in dry areas need to travel for a fix, drunk-driving accidents are far more common. For homebodies, drug-abuse rates can increase. Researchers at the University of Louisville found that dry counties in Kentucky were nearly twice as likely to be caught hosting illegal meth labs as their wet neighbours. No wonder punters from Kansas to Maryland have voted to relax prohibition in recent years. If for no other reason, letting in the booze makes financial sense. One study from 2014 found that turning three dry Arkansas counties wet could bring in over $30m a year to the local economy—good cause for cracking open a bottle or three.