From this CNN story:
http://www.cnn.com/2004/TRAVEL/09/28/ponderosa.reut/index.html
I went there in June of this year, just happened to be driving by with my SO and on the spur of the moment, we thought we would check it out. It was actually kind of cool - great scenery, some old cars and farm equipment, touristy-shops, and of course, the Ponderosa Ranch where many of the exterior, and some interior shots for the television series Bonanza were filmed.
Sorry to hear it has closed. It wasn’t Magic Mountain or Disney World, but as far as tourist theme parks went, it was a nice nostalgic trip down memory road.