When Nevada first started their bighorn hunting season, there were a couple stipulations for hunters before they could get their permits. First the hunter would have to attend a class. Then once they received the bighorn permit they would have to take a specific powered scope or binoculars in the field.
Nevada Department of Wildlife had these stipulations because they were trying to help boost the bighorn populations. With the scope or binoculars hunters were better able to guess the bighorn's age and not hunt the younger ones. Now with the current bighorn population there is no class needed before getting one's bighorn license, and no need to ensure the age of the bighorn either. From KTVN.com .