Colorado has so many mountains; why do you have to steal those from neighboring states? :-) Consultation of a topographic map or Google Earth will show that the Abajo Mountains lie well west of the Colorado-Utah boundary.
Good call, thanks. The data I was working from was referring to geologic provinces without regard to what regions were actually mountainous. Obviously, I neglected to manually correct for that.
I'm curious about the source of your data -- did it not include the Never Summer range? It might be considered a subrange or too small to make the list, but I am not sure!