It sounds like they do fine; only beer in 100 miles is a pretty good business proposition. They also go through 1200 pounds of pinto beans a year, so somebody's buying food there.
That's about 3.5 pounds of beans a day. Which would make maybe 4 or so gallons of soup, that's 512fl oz or 32 16oz portions.
1200 lbs a year, assuming a half pound per serving, is only 2400 servings a year, or about six a day. I can't imagine six bowls of beans does much to pay the bills even in rural Montana.
A half pound of beans is an awful lot for a serving.
Really? The recipes I found seemed to use 3 1lb cans of beans per 4 people. That's 3/4 lb of beans per person. Also, this is Montana, they don't shy from larger portions, a pound a person wouldn't surprise me.