I didn’t pull the HUD data to dive too much into it. The link to the source I gave had this though for your second question:
[One source of data was places] That provide temporary shelter during extremely cold weather (like churches). This category does not include shelters that operate only in the event of a natural disaster.
They may also be unemployed seasonal labor, so they have work sometimes (agriculture, tourism, ranching, etc) but not enough year round income. Just guessing on that, I’m not much familiar with Montana and the Dakotas.
Check out the full info at the links though. I’m a but sleep deprived to do much in depth analysis on this today. 😔