Hi, Kevin. Welcome to WhatBird.
Great photo... definitely a hawk. Cooper's Hawk is my opinion, although it's hard to gauge the size of it. It's prey looks like a rabbit (or house cat!), which would be the upper limit of prey size for a Cooper's. If it's larger than I think it is, it may be a Swainson's Hawk.... but Cooper's is my pick.
Edited: added below comments.
Well, guess I really blew this one!! 
I found where this was on another thread, and the concensus was for a Northern Harrier. I didn't judge it's size to be that large, although the rabbit, (now that I know what it is), is an indicator. Of all the hawks I have seen, I have never positively ID'd a Northern Harrier!! The picture in my bird book looks nothing like the posted photo... but I realize that book drawings are meant to be a guide only, not a basis for absolute identification!! I've learned from this.....
We did not inherit Mother Earth from our ancestors...... we have borrowed Her from our descendants.
Chief Seattle (paraphrased)
