From vintage scholastic cover:
"Is Ruby a town?"
"It's a ghost town," the ranger explained. It's only inhabitant is white-bearded mayor Abe Winters--until a rock slide and broken piston rod add the hard-up Deans--Dad, Tom, Betty, and Chuck.

How they revive Ruby, foil real-estate sharpsters, and lure tourists with fishing, flapjacks, and gold dust is a ghost-town adventure. Another Rutherford Montgomery story--fun and romance.