Young bald eagle?
An Audubon field trip to the home of one of our members, primarily to see the Rosy Finch at this high altitude. Just as we were leaving this group of Cassin's Finch flew in to a tree.
One of these days I'm going to invest in a nice camera with a lense that can actually zoom. Until then, this crummy phone camera will have to do.
In any case, the bird on the post was definitely a red-tailed hawk and it was eating some small animal, probably some rodent. The hawk flew away before I could get very close but I did see fresh blood on the post where it had been eating.