WAPITI VALLEY, Wyo.

EVERYONE here seems to know the story of the house on the hill. The rambling log structure, with its undulating staircases, umpteen balconies and fun-house warren of half-finished rooms, has for nearly 30 years loomed over the Buffalo Bill Cody Scenic Byway, inspiring stories. Lots of stories.

A sampling: At a nearby shop that sells elk-antler chandeliers, the clerk said that the house appeared to a man in a vision and that he built it as a monument to the town. At a filling station, a motorist who had stopped for soft-serve ice cream said that the house was meant to be a lookout tower if an underground volcano in Yellowstone National Park ever erupted. And the teenagers who break into the abandoned structure on Saturday nights point to its writhing balustrades of warped pine and insist it was built by a madman.

“None of them are fact,” Sunny Larsen, 32, said of the tales. Ms. Larsen should know. Her father, Francis Lee Smith, is the one who built the house, and she and her brother, Buckles (or Bucky), spent part of their childhood there.

Still, it’s hard to pin down the truth about why Mr. Smith, an engineer, labored single-handedly for more than a dozen years on a house that calls to mind grand follies like the Winchester Mystery House in San Jose, Calif., built by the rifle company heiress Sarah L. Winchester.