Wait, what?
This gruesome sight greeted me recently not very far from where a roosting Great Horned Owl was being yelled at by Blue Jays. 
Suspicion isn’t evidence, but caching of prey is something these big owls do. Especially in nesting season. The male has to hunt more than usual since the female spends so much time on the nest; these birds are some of the earliest to nest and they have to be vigilant about keeping the eggs warm in late winter.
A couple of sources note that the owls will sit on frozen prey to thaw it out.
Red-tailed Hawks will also cache food. So will American Kestrels. I’m sure many other species do, too, but these are the ones I’ve seen do it. And I don’t know if there’s more than one Great Horned Owl here.
Backyard and Beyond 
Nice find! At a nature park near my house a raccoon had crawled onto a large limb over a creek beside the trail and then, apparently, just died there. It sat in that position for months, withering and shrinking. It was an attraction on the trail for all of us biped mammals.