The Lutz Canyon trail offers the most direct route to the summit of Miller Peak. It climbs a total of 3775 feet, starting in the bottom of Ash Canyon, climbing through Lutz Canyon to the the Crest Trail, then up the Miller Peak trail to the top. Total distance is 4.7 miles one way, and signs mark all major trail junctions. Much of the trail is shaded by surrounding trees. Hiking time can be as little as three hours up, two down.
To reach the trailhead from Sierra Vista, head south on Highway 92 approximately 12 miles from the Fry Boulevard (Highway 90) intersection to Ash Canyon Road and turn right. Ash quickly turns to a graded-but-rocky dirt road that runs through a residential area before entering the Coronado National Forest. Stay on Ash until you reach a fork, then take the righthand/uphill road marked "Lutz Canyon." In about a half mile this road deadends at the trailhead.
With care you can take a passenger car the whole way to the trailhead; on my recent hike I returned to find a dusty (but apparently undamaged) Kia Optima parked next to my Jeep.
From the trailhead the path is wide and shaded. It's relatively level until it leaves Ash Canyon and begins climbing Lutz Canyon. About the time it begins to get steep, about a mile in, the first switchbacks appear. Another half-mile later the trail reaches a large pile of mine tailings which provide a convenient viewpoint to look down-canyon. You're about 1200 feet above the trailhead at this point, which is marked "Lutz Tunnel" on the Miller Peak topo map (1:24,000). The tunnel itself is a hole bored deep into the mountainside. Its entrance has been filled in with dirt and an appropriate death-or-serious-injury sign marks the spot.
Above the tunnel, more switchbacks take you another 1000 feet (in altitude) up the canyon. The trees thin out until you're in shadeless territory hemmed in by waist-to-chest-high manzanita bushes. The trail levels out and follows a contour for awhile, taking you past another mine tunnel, before another series of switchbacks brings you to the Crest trail. There's a good level spot here to take a break, and a sign helpfully points out that Miller Peak is to your right.
The Crest trail is shady and level for a stretch, passing the Bond Spring trail, then begins climbing via more switchbacks, and very shortly intersects the Miller Peak trail. From here, it's a quick half-mile to the top.
Despite the ample shade along the route, remember to take plenty of water.
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