Montana is 600 miles by 250 miles and has almost no people living in it. It’s entirely unsurprising that people who choose to move or stay there want to take up lots of space. As for racial makeup: Montana was largely settled by people given free land in return for moving there, and then in the late 19th century a mining boom; during that era local laws were quite discriminatory. It hasn’t recently had any booming industry that might attract a wide variety of immigrants.

Billings is the largest city and has only 160k people. Billings is spread out along a federally funded interstate highway, and has plenty of available land. It’s a place with harsh winters that would be rather unfriendly to pedestrians/cyclists anyway. 95% of households own a car, and on average there are about 2 cars per household. (For contrast, in NYC there are about 0.6 cars per household.) As far as I can tell buses are the only public transit in town.