Houston is about 18 times bigger than Missoula.

Missoula (map shows its 17 named neighbourhoods; the area covers the whole city) is approximately 91 sq km, while Houston is approximately 1,659 sq km, making Houston 1,728% larger than Missoula.
Tip: This to-scale comparison of Missoula vs. Houston uses the Mercator projection, which distorts the size of regions near the poles.
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