n. — historical, Western Canada, especially Alberta
an establishment selling or trading whisky illegally to Native hunters; a whisky post.
Type: 1. Origin — Whisky forts, primarily located in late 19th-century Alberta, sold whisky and other goods to Aboriginal peoples (see the 1991 quotation). At whisky forts, alcohol was most commonly traded for furs (e.g. buffalo robes) in addition to items such as guns, ammunition and horses (see the 1994 quotation). Trading was done through "a hole a in the wall" (see the 1909 quotation) or "wickets" (see the 1994 quotation), as Aboriginal peoples were not allowed inside the fortified establishments.
Whisky forts were established as a result of American expansion, as Aboriginal people, particularly from Montana, were drawn to the "unpoliced southern prairies of western Canada" (see Canadian Encyclopedia). Although there were more than 50 whisky forts operating in Alberta (see the 1991 quotation), the most notorious one was Fort Whoop-up, in Southern Alberta. The earliest attestation of the term describes this establishment (see the 1909 quotation). The end of the whisky fort era is credited to the arrival of the North West Mounted Police (see Mounted Police, Mountie, the 1996 and 2005 quotations, OCCH reference).
This term is marked as Canadian origin, appearing in no US or international dictionaries in our set. As seen in Chart 1, the term is most frequently used in Canada.
See also COD-2, s.v. "whisky fort", which is marked "Cdn hist.".
See also: Mounted Police Mountie whiskey post
- 1909  One of the most notorious of these centres of evil was "Whoop-Up" or Fort Hamilton, situated at the fork of the St. Mary's and the Belly rivers, but a few miles southwest where the town of Lethbridge now stands in Southern Alberta. This whisky fort was well stockaded, and well supplied with muskets and a cannon. Through a hole in the wall a drink of whisky could be bought for a buffalo robe, and after having made the Indians drunk it was no uncommon thing for the vile garrison to "pot" the reeling savages outside. After a time other traders came up who sold the Indians other things besides whisky, among them rifles and ammunition. 
- 1954  At the junction of the Belly and St. Mary's rivers it found Fort Whoop-up deserted. This "whisky fort" was one of the main bases of operations for the outlaws and desperados who exploited the Canadian Indians. 
- 1991  "To my knowledge, it was the most notorious whisky fort in southern Alberta," says Rochelle Good Striker, a historical interpreter at the Lethbridge tourist attraction.
"The fort was sort of like a liquor store in the natives' backyard. It became the hub of southern Alberta."
Armed with $10,000 in trade goods, Americans Alfred Hamilton and John Jerome Healy built the original structure in 1869. A year later it burned down, but business was so good they had a new fort up and operating in 1871. 
- 1994  Of the many whisky forts, Whoop Up was the most formidable. It had high palisades loopholed for riflemen, bastions mounted with cannons, and ramparts patrolled by gunmen. Indians were not allowed inside. They did their trading through wickets. In exchange for a devil's brew that would drive any consumer out of his senses, the Indians traded buffalo hides, guns, horses, even wives and daughters. 
- 1996  Macleod protected the original recruits from the worst excesses of French and respected Potts and the Natives, which won him friends on all sides.
It wasn't so much the Mounties closing down whisky forts as the Americans who ran them realizing there was little profit in continuing to run them. 
- 2005  When the North West Mounted Police brought the rule of law in 1874, they found the whisky forts empty. The traders weren't exactly put out of business -- the provisions that sustained the Mounties until the railroad came in 1883 were supplied by those same traders who drove their freight wagons north on the Whoop-Up Trail from Fort Benton, Mont. 
- 2011  Vanderhaeghe has an eye for the larger implications. Whether it be the repercussions of westward expansion, with its whisky fort brutalities, missionary bungling, and spread of contagion so devastatingly rendered in The Last Crossing - the image of the native village ravaged by smallpox lingers still - or the horror of the Cypress Hills Massacre in The Englishman's Boy, an event instrumental to the founding of the North West Mounted Police, he is keenly aware of how consequential the seemingly inconsequential can be. 
Images:
Chart 1: Internet Domain Search, 25 Jul. 2014