It doesn't really help that Berlin keeps 5 Red deer / American elk taxa in that part of the zoo... At least the Bactrian red deer and Atlas deer can be excluded easily. I would go for either the Altai wapiti or the Tule elk, slighly favouring the last option....
Funnily enough I had the recollection when I first saw the picture on my laptop that it was Tule Elk, but when I looked at other pictures I was less convinced.
