The house shown at the end of the episode is the Bowers Mansion found at the Bowers Mansion County Park, Washoe Valley, Nevada. In this story, it's depicted as the home constructed by Annie after getting rich.
Annie: (to the pallbearers about to lay the casket to rest on a hillside) Would you turn him around so he can see the saloons? Then he'll know he's not in a heathen land.
Adam: Let's get back to the Ponderosa, Pa. This isn't any of our affair.
Ben: Now son, we can't ignore the rest of the world. We're the only stablising influence in the country.