Between Manville and Lusk, Wyoming, 2/5/12. Best I can tell, this is a Red-tailed hawk, but there are a lot of shading variations in both red-tailed and red-shouldered hawks. Any Foruminants have a clue?
[Update after Repete's comment: Looking at Google images of Ferruginous Hawks, I think Repete is right, although I'm still not absolutely convinced. Google images of the other two hawks show various shadings at different maturity stages. Oh well.]