Bird was perched in large cottonwood tree in close proximity to Bear Creek Greenbelt near the creek.  Hawk size, with striking orange bill and bluish tip.  Long white neck with barring on the lower parts.  Dark cap and belly with white underneath.  I am familiar with this bird from time spent living and birding in Texas.  Confident in ID.  

A quick word on why I'm just now reporting this bird.  When I observed this bird I was not routinely using the eBird app in the field nor was I carrying a camera (as I do now).  Bird sightings were a check mark in my field guide. I now use eBird everyday. I am currently updating my eBird life list and this is one of the birds I wanted to add to my Colorado Life List.  Since I did not have any photos of the bird and it is a rare bird (actually a 1st sighting for Jefferson Co, Colorado, I believe) I did not think it would be a confirmed sightng for lack of supporting documentaton.  However, using the tools in eBird, I was able to confirm that this same bird had been seen by others on August 24th (the day I observed it) as well as on the 25th near where I had observed the bird so that would give strong supporting evidence to my sighting.  Hence my reason for reporting it now.