Hi TPC. My Peterson Flash Guide came in the mail today, thank you. I am now convinced that it was either a Peregrine or a Cooper's that I saw on Saturday. When I said that it was low, I meant like 20 floors up or so, but close enough to see the markings. That being said, I have seen Cooper's Hawks close to there before so that's more likely what it was. Thanks for the guide it's small enough to go in my purse. Now if I could just remember to take my binocs everywhere with me..