Around 1908 an extensive system of tunnels were dug beneath Moose Jaw with the intention of running the city on steam power. These were quickly abandoned, and the city's underbelly moved in.
First were Chinese immigrants. Some of them were indentured servants, some were railroad workers, other opened laundromats and restaurants to cater to the population of mostly single, male miners. In order to avoid the head count tax, many of them went underground—literally. They operated their businesses and even in some cases lived in the abandoned tunnels beneath Moose Jaw, where they could escape the racial persecution of Yellow Peril.
When Prohibition hit in the 1920s, the tunnels had a new purpose. Rum runners used them to store alcohol and covertly transport it to the Soo Line Railroad, on which the liquor would be snuck into the U.S. Eventually there were even functioning speakeasies underneath the streets of Moose Jaw in addition Ever since, there have been rumors that Al Capone was involved in the bootlegging industry in Moose Jaw and even lived there briefly to avoid the feds, though only anecdotal evidence exists.