the history of the Pondorosa
Over at the board for The Big Valley a thread: https://moviechat.org/tt0058791/The-Big-Valley/5cbb5bf7e1b1a8743133c818/The-size-of-the-ranch?reply=5ce60656014be45ed164fdf4 sort of got off topic with a discussion of the history of the Pondorosa and the birth years of the Cartwrights.
And some fans of Bonanza might be interested.