During the wave of faux-Polynesian pop in the 1960s, any city worth its salt had to have a tiki bar. Great Falls, Montana was no exception.
Nevermind the fact that it was nowhere near the tropics. Nevermind the fact that the only body of water nearby was the Missouri River. Nevermind the fact that it was too cold to swim for most of the year. The people of Montana wanted a tiki bar and they wanted it pronto.
So in 1962, the proprietors of the O'Haire Motor Inn opened the Sip 'n Dip Lounge as part of their motel. It was loved by visitors and locals alike, and as such, is one of the few surviving tiki bars to survive into the 21st century.
The Sip 'n Dip's primary claim to fame is its view of the indoor pool. Until 1995, the giant glass panes behind the bar allowed patrons to gaze upon the cool blue waters and the occasional swimmer. Nice enough, but at a New Year's Eve party the owner stepped it up a notch by having live mermaids swim in the pool. They've been a fixture ever since, as well as a handful of mermen.
The Sip 'n Dip Lounge is still going strong after 50+ years, though not a lot has changed. The South Seas atmosphere and drinks menu are mostly the same, and even the same in-house musician they've had since 1963 ("Piano Pat", still jazzy in her 80s). In addition to mermaids in the pool, you may also see hotel guests swimming around. Sip 'n Dip regulars report the occasional skinny dipper, despite the motel's warnings.