Montezuma Pass is a tough over-and-back mainly-gravel ride from Parker Canyon Lake to the flats south of Sierra Vista. The over-and-back is 41.8 miles with about 4,700 feet of climbing. If you descend only as far as the Visitor Center on the east side of the pass, you save almost 6 miles of paved road riding and about 500 feet of climbing, giving a ride of about 36 miles and 4,200 feet of climbing. When we did the ride (4/18/22) there was a fair amount of washboard which made the ride quite brutal as well as being difficult from all the climbing on dirt.
The west side of the pass is much longer and has a lot of rolling terrain and gradual hills, but the real drama of the pass in on the east side, with beautiful switchbacks descending rapidly into the canyon.
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From I-10 drive down Highway 83 towards Sonoita. From Sonoita continue south on Hwy 83 for almost 29 miles to the Parker Canyon Lake Marina, where you can park. The ride from Sonoita to Parker Canyon Lake is a wonderful road bike ride.
From the Marina, climb steeply up the paved road the way you came, for 0.6 miles to the big dirt road on the right. Follow this over three short climbs then a long gradual descent, before you start the long climb to Montezuma Pass. Eventually you will see the best part of the climb as it slashes up across the hillside until you finally reach the pass after about 14.7 miles.
The east side of Montezuma Pass is much more dramatic, and you can look down at the beautiful dirt switchbacks that lead down in to the canyon for just over two miles before you reach paved road. Another 1.3 miles and you are at the Visitor Center, where you can refill your water bottles. Many people turn round here.
Continuing down the paved road until it reaches the flatlands and turns sharply to the left adds just under 6 miles and about 500 feet of climbing to the out-and-back ride.
Wherever you turn around, the 2 miles of dirt switchbacks will give you a good workout before you reach Montezuma Pass again.
After such a short climb from the Visitor Center, the 14 miles of dirt from the top of the pass back to Parker Canyon Lake feels like a long way. Especially depressing is coming back up the long bleak gradual climb before you reach the final three small climbs. It felt so easy on the way down!