Thank You all for your thoughts. Unfortunately, none of those sounded like what I heard & saw. I'm starting to think maybe it wasn't a bird at all. Maybe a Large Carpenter Bee - as those are large & they buzz Loudly. It was as loud as a cicada - but not that. Wish I would have taken a picture, but it was so fast, probably wouldn't have gotten one anyway.
Recently visited Southern Colorado. Suddenly heard a very Loud Buzzing sound, looked up & saw a fast flying yellow bird? soaring in the sky. Never went by the hummingbird feeders - just kind of soaring & buzzing - very LOUD - what did I see??? It was mid-afternoon..... This is driving me crazy - I want to know what I saw....Thank You!