I believe the Swanson Hawk migrates. We see them in the spring, Have always watched them when I disked, they look for the mice that are forced to find new homes. They are tough on baby jackrabbits too. Their broods are usually out of their nest by the time we cut alfalfa, but are not feathered and can not fly. This is when you see them feeding their young. The ones we see later may be families.
We see a few Red tails too, but I don't think they like open country. It seems you see them in the same places year after year. I think they like to be near wooded or brushy areas. The Northern Harrier can be seen here the year around. There also is a small black hawk that likes to stay in trees, we see it in the winter, I call it a pigeon hawk. I think it is a bird eater. Often it is seen flying with 2 or 3 birds following, maybe they are trying to harrass it or chase it away.