I used Terrain2STL (http://jthatch.com/Terrain2STL/) to get the base model, cut out California, exaggerated the terrain, and made it look nice using Blender.
Terrain is probably not to scale, but you can modify the z axis scaling to change it however you'd like
This is my first upload here so any feedback is appreciated.
CaliTopoModel.stl | 62.2MB |