Missoula is about 4.8 times smaller than Montreal.

Montreal is approximately 432 sq km, while Missoula (map shows its 17 named neighbourhoods; the area covers the whole city) is approximately 91 sq km, making Missoula 21.02% the size of Montreal.
Tip: This to-scale comparison of Montreal vs. Missoula uses the Mercator projection, which distorts the size of regions near the poles.
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