Canyons are inherently risky. Flash floods occur without notice on sunny days. Technical skills & surrounding topography knowledge required yet does not eliminate risk.
Why Didn't I Use the Trail!!
Hershberger Peak via Marble Canyon (south)
The most athletic approach to reach Hershberger Peak, the highest point along this section of the frontal range, would be via Marble Canyon, using the southern most drainage. This is an exceptional hike, with a wide variety of terrain including numerous waterfall obstacles, rock jumbles, narrows (...even mini-slot section replete with water!) Initially the gradient is mild, exploring and enjoying the winding course of the drainage as it slowly increases in gradient, and then the challenges become ever more demanding. There are a few areas that will pose a bit of an exposure problem... more perceived than real. Most of the dry falls can be hiked steeply around if you choose not to climb the rock surfaces. Nearing the top of the drainage proper, the slope is impressive until it terminates in the large rock overhang known as the Amphitheatre. From there you move around to your right, skirting the edge of the rock formation and moving upwards to the adjacent ridge on your right, though you may also simply move ever upward staying below that ridge. The peak is just above a few hundred feet... any route will get you there.
If it is still the winter months, plan on snow.
Once on the peak, consider the time of day in choosing your return path. You may traverse a little further to the east connecting with T119 for an easy path back down the mountain. Or, you can return down the ridge and enjoy the steady off trail hike across the Mesa ridge, hitting Big Peak, Little Peak, then dropping into the RockaChucky drainage, descending back to Alamogordo. If it is later in the day and darkness threatens, you'd do better to take T119... steep, but it is a trail.
This route up to Hershberger Peak is a canyoneering route... not to be taken lightly. The entire hike up is off trail. Be in shape and be prepared.
It would be a very good idea to know your options. Print out the maps and specifics for all the various return routes. I prefer The Mesa via RockaChucky, but if you are coming down that route for the first time, route finding might be confusing unless you have a good idea of where you are headed.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.