Ok, I just got the crap scared out of me. I am 55 years old and have lived in SW Iowa all my life. I have lived here 36 years and my grandparents lived here 50 years. As far as snakes go I only see a few Garter Snakes, an occasional Bull Snake, and one Blue Racer when I was about 10, until today that is. I think I just saw a Rattlesnake. It was only a quick look as it slithered into the tall grass but it had a diamond pattern on it. It was not a large snake, 2-3 feet I'd say and about as big around as a 1" pipe. It was vibrating it's tail very rapidly but it sounded more like a bumble bee than a rattle. So my question is was this a rattler or is there another snake that mimics the rattler by vibrating it's tail? The last report of a rattler I heard of in this area was back in the 1960's. I may never walk through the tall grass again, yikes!

Gray rat snake - common and beneficial - as the name implies, eats rats, mice, etc. Tucker

Yes, it is a Florida Pinesnake (Pituophis melanoleucus mugitus). Not a common sight.

You should have started a new post rather than adding to the other snake post. The is a Gray Ratsnake (Pantherophis alleghaniensis although sometimes still known as P. obsoletus in older references). You didn't say where you where, but this looks very much like the gray rats we used to get in South Carolina near the Georgia border.