It does not take very long for bull elk to grow antlers. Below are the words of Jeremy Banfield, Pennsylvania Game Commission elk biologist.
Bull elk antlers start growing in early April and are typically fully grown by mid-August. As of today (6/5), the antler growing season is almost halfway through.
Most bulls have clearly developed brow tines (the first two tines just up from the top of the head) as well as a third or even fourth point starting to branch off of each of the main beams. Elk antlers can grow up to one inch per day and are the fastest growing antlers in the deer family (deer, elk, moose).
The bull pictured here will likely develop a 5 X 5 or maybe a small 6 X 6 rack.