What are the differences between male and female elk?

In most species of deer, only the male grows a yearly set of antlers, while the females have only stubs. However, "reindeer" (caribou), like the moose, occupy their own genus of the deer family and both genders have antlers. In the Scandinavian variety, older males lose their antlers earlier than young males (in December), and only females keep their antlers until summer. (This would mean Santa's reindeer are perpetually young, or female?)