The High School I teach at had a Swainson's Hawk monitoring project for years. Built nest boxes, checked numbers, etc. we are a stopover for them too.
Easy to ID...the leading edge of the wing is white (there is a dark morph of the bird, but is uncommon) in adults. They eat a lot of insects like hoppers...which led to a drastic reduction in their numbers in Argentina in 1996. Over 20,000 birds died in a small area after eating insecticide-laden (monocrotophos) hoppers...
They are coming back strong out here, but we have a smaller population than the midwest and plains states