Looks like the Wall grain elevator will keep their service. That's the only industry I "know" on the line, as I've been taking pictures of it every time we go through there since 1983. It's earlier appearance is the inspiration for one of my elevators, although I don't have nearly enough room to do it justice, even in the 1983 version. And they've grown a lot in the last 30 years!
If you're out there, they're next to Wall Drug, and unless it's the middle of harvest season, they're nice people who'll answer any questions they can about the grain elevator and the industry. Leave the family at the tourist trap and do some research.
Wall Drug is fascinating as well, so you might as well go through it with the family, then leave them to look some more.