What makes a 180" mule deer?

Back in the 60s and 70s, I spent the early winter months with my left eye plugged into a spotting scope watching mule deer bucks. It was in those years that I came up with a system to judge the rack size of a buck in the field. It came about after many hours of judging them on the hoof, and then in the spring picking up their drops and gross measuring them. While guiding during the same time period, I measured many harvested bucks. These two practices gave me the opportunity to develop a rack bracketing scoring system. The motivation came while I was guiding clients who required me to know the B&C gross class of the buck before they squeezed the hammer.

Let me go through my system for field judging a buck. You can start by using the ears and a few other simple rules to help determine if the buck is a 160, 170 or 180-class gross buck. This is my “Rack Bracketing System” for field judging a gross rack score. The system isn’t designed to give a net score, but with some practice you will be able to narrow the gross score down to high, mid, or low 170, 180, or a super 190- buck.

First determine the distance between a buck’s ears, ear-tip to ear-tip across the forehead. This measurement will be used to evaluate inside spread width. Unfortunately mule deer ears will vary in length from 9 to 10 inches depending on the unit or state. In addition some bucks in certain units will have bigger heads adding to the ear tip to ear tip length. In my experience Wyoming and Idaho mule deer, tip to tip, will vary from 21 to 23 inches. However in Colorado and Utah ear widths will be 24 to 25 inches. I guarantee that there will be exemptions to the rule in all western states, but this is a beginning benchmark. Saying that, you need to gather your own ground knowledge for the units you personally hunt.

My first rule for judging is what I call “good fronts will make up for bad backs.” The “fronts” include the three measurements:

1.  The inside spread (determined by comparing it to the ear-tip to ear-tip length)

2.  The length of the G-4 points (points coming off the main beam)

3.  The length of the two main beams (visually take the length of an ear, end over end, up the main beam to come up with a sum total. Three ears = 27 to 30 inches)

It’s easy to evaluate the length of a G-4. A long G-4 can almost reach as high as the back tines in length. A short G-4 ranges from 4 to 6 inches in length. Remember long G-4’s are a sign of a good main frame.

These 5 measurements (the inside spread, two G-4’s and two main beams) in inches will usually add up to 49 – 60% of the bucks total rack score. So this is the most important section of a racks score.

Make sure you pick up a copy of the Public Land, DIY Issue (EHJ 139) where you’ll be able to read the full version of this article, along with accompanying photos that really drive my point home. This issue will be going to the printer very soon, so renew or subscribe today to ensure you get it.