I've made my stance clear on the Huachucas before, there are positives and negatives. The positives always seem to win me over. Miller Peak with it's awesome panoramas is always worth the effort. It can be reached via Miller Canyon for a tough and rewarding climb.
The signed trailhead takes off right of the gravel road and starts climbing immediately. Within a quarter mile you see a signed intersection, keep going straight/left to Miller Canyon/Peak. There are plently of manzanitas along the way. Shortly thereafter a sign welcomes you into the Miller Peak Wilderness, with a nice view of Carr Peak. After about 2/3 mile there is another signed intersection for a short trail to another road, which breaks off to your left. Keep going straight. You may start to notice running water on your left, the lowermost drainage of Miller Canyon. It was running strong today from the recent rains.
In a touch over a mile the wide jeep track unexpectedly splits, and there is no sign to point the way. This is the only would-be route finding issue. Simply go right and climb. The track soon crosses over the creek bed, which now starts to fall away slowly to your right. There may or may not be water here, depending on when you go. Today there were little falls everywhere. This is forested and very pleasant. The sound of forcefully running water makes it even more so.
Just climb away for about another mile. About 2 miles in, there is a sign pointing you right to the Crest Junction (also called Bathtub Spring), which it says is 2 miles away. You cross over the creek drainage here and it's now on your left. You will start to gain altitude seriously now as you switchback up the wall of Miller Canyon. The creek drops farther away..only to come back later as you cross over it a couple more times. Every crossing is followed by climbing away. Finally, after about 3.25 miles you really do climb out of the canyon, which you can see severely cutting away below you. You can tell that you are coming to a saddle.
At 4 miles you reach the junction with the Huachuca Crest trail (103) which runs the length of the range. This is also a segment of the Arizona Trail. Hang a left here to Miller Peak, as the sign says (2 miles and some change). Immediately you come to Bathtub Spring, where there literally is a Bathtub spring. Keep going south along the crest trail. Sometimes this trail is nearly choked over with plants but it is well established. You cross over the head of Miller Canyon, which is sweet. There are also intermittently great views of Miller Peak ahead. Today it was wrapped in clouds and looked sinister. Would I make it? An amazing wildflower display and intermittent aspen stands encouraged me to try.
After about 1.5 miles on the Crest trail you come to signed intersection for the formal trail to Miller Peak (#105). This is to your left. I must say that the Crest trail was the cleanest I have ever seen it, essentially spotless and unbelievably pleasant.
Take the trail to the peak, about half a mile and 500 feet. It is no small last chore. However, the peak greets you with probably the best Sky Island summit view in southeastern Arizona (though others are very close). The threatening sky only added to the majesty. Take it in and head back the way you came.
In summer there is a good chance you will be racing the monsoons so plan accordingly. The sky looked horrible by the time I finished. Also, obviouly beware the border crossers. I saw none today, probably because it was a weekend? I don't know but you may want to consider climbing this one with a buddy. In other words, be smarter than me.
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.