San Diego to Denver maiden voyage for the newbies

The Good Sam Trip planner initially took that route, but it looks like it might be more mountainous? It looks like the 15 goes along the base of some major mountain ranges, but it also looks like we'd have to go trough a few mountain passes, too. It's hard to tell how tough those passes might be.

We're trying to find a good topographical road map. We can see the mountains on the Good Sam map, we just can't tell how severe they are...