James H. Gray, Booze: The Impact of Whisky on the Prairie West (Scarborough, ON: The New American Library of Canada, 1974), p. 28.
In the main the Mounties concentrated on the rum-runners who brought contraband into the Territories from Manitoba, North Dakota, or Montana [in the 1870s and 1880s]. Incoming train passengers were patted for suspicious bulges, and unusually heavy baggage was opened and inspected. The penalty for being caught was loss of the liquor, which was poured down the drain. The largest hauls were made in the over-the-border trade, for across vast stretches of the prairie there was no place to hide when a Mounted Police patrol was attracted by the dust kicked up by a bull train laden with whisky. This happened frequently enough to make a show, statistically, in the tabulated reports of annual seizures. When such seizures were effected, regulations required that the liquor be taken to the nearest post, where it was spilled on the ground under supervision of superior officers.
There are widely believed legends in the west that in most of the Mounted Police posts the spilling was done in a carefully selected spot where earth-covered containers were previously installed to catch the booze. Such was the quality of the liquor sold in the west that nobody seemed overly concerned about drinking stuff that had filtered through a foot of mud and a couple of discarded horse blankets. 
14. Eric Wells, unpublished manuscript, Winnipeg, 1967.