Since you have horses, you are in a much better situation. You should be able to get your Dad to most places and do so with a lot less struggle than the backpack crowd. Not sure if you have three points in WY, or your group averages three points.
I would not hesitate to burn those points in Wyoming. A 3-point unit in Wyoming is usually a really quality experience, with less hunting pressure than you will likely encounter in CO.
I assume you are talking about rifle, not archery. I would apply to a unit in WY and if not drawn, use CO as your fall back option. You will have your WY results well in advance of having to make a decision on CO.
Good luck.