On top of S Dino Egg in the Flatirons about 3 weeks ago.

Raptor on S. Dino Egg eating something. Taken by John Brooks. 105937340 Submitted By: Rick Blair on Jul 3, 2012

I'm going with Peregrine Falcon. The flattish head, large eyes and slightly shorter and sharper beak match. The coloring is also more like a Peregrine than a Red Tailed Hawk.

Prairie Falcon

Prairie Falcon for sure. Peregrine's have a larger and darker 'mustache' as well as overall darker body marks. It also appears to be eating some sort of small mammal which is the Prairie Falcon speciality compared to the Peregrine that specializes in avian prey.

I stand corrected, gentlemen. Good call. I've never seen a Prarie Falcon, so I didn't make the connection.

Wow, damn cool photo. Beautiful bird.

Thank you all very much! I have been trying to figure this out for a while! I was not even considering the correct bird.

I live in Downtown Denver ( 5 points ) and it never ceases to amaze me the wildlife encounters I have in the Flatirons, many trailheads being less than a half hour from my front door. This was an after work scamper.

This bird did not like us being up there and even more it did not like the other birds flying around. It let out many screetches at all of us. It was also very large.

I'm guessing the thing in its tallons is either a squirrel or a prairie dog, too small to be a chipmunk.

I was hoping this was a who would win in a fight kind of thing

Peregrine for sure!!

Sorry John, I'll try to dig up the photo of the Pacific Giant Octopus I saw on top of the 3rd Flatriron but in the mean time check this out.