Thanks so much for the reply and link. I had thought about something like this using the perspective tool in PS Elements, but I have yet to try it.

When you do this do you put your rivers or other features in first, then transform it?

As I practice I tend to put the mountains in first so I kind of know where the rivers are coming from, but it probably wouldn't be a good idea doing them until after I transform the top down land mass. I guess I would have to just practice putting in the rivers so they fit the isometric perspective. More width, not as much height, as the video shows. Or, do the rivers first and then transform.