This young ram has horns it looks similar to ewe, however if one looks at the base diameter and the diameter at the center of the horn there is quite a difference. Eventually this Ram will grow a very large set of horns

Desert Bighorn 101 - Lecture 2 - Horns of the Bighorn

It could be said that all Bighorns have horns but not all Bighorn have big horns. While this sounds a little bit confusing, basically it means that both male and female Bighorn sheep have horns. However their horns are quite different from one another in both size and structure.
 
The ewes have much smaller horns than the rams, which can make it difficult to determine whether one of these animals is a ewe or young ram. With careful observation and a little knowledge this can be done.
 
If you look at the females horns you will see that the diameter of the horn at the midway point is about the same as where it enters the skull. This is quite different from a young ram. Looking at the diameter of the midway point on a young ram and the diameter of the horn where it enters the skull we find the base diameter is much larger, giving the horns of a young ram the look of a bent triangle.
 
 
Another important thing to know about all Bighorn sheep is that their horns, are permanent. They do not shed them yearly like deer and elk. This is why many mature rams that have been through many fights have horns that are blunt, and have the tips broken off. Among people who know Bighorn sheep, this is often referred to as having been broomed off.
 
 
Many of the characteristics of the horn such as size color and texture are unique to that individual, as well as the herd it belongs to and its particular species.
 
I hope this will help you as you walk the desert in your own personal quest for knowledge and experience.