Osprey
ClearCreek
You didn't mention a general location of the nest? I would agree it likely is an osprey if it's in an area where ospreys are found. Every year we see new nests similar to this on telephone poles by ospreys. The power companies tend to tear the nests down when ospreys first start establishing the nests. Then, often build a platform with bird guards in proximity to where they build the original nest. There are osprey nests scattered pretty much everywhere close to reservoirs here in the north front range in Colo. Osprey and bald eagle numbers have been increasing just about every year in our area. There are videocams on several of these nests for those interested in watching them.
I'm super excited that cheatgrass is getting good exposure but it doesn't look like cheatgrass in the nest to me!
We focus on trophy elk, mule deer, antelope and moose hunts and take B&C bucks most years.