Organ Pipe Cactus National Monument
Organ Pipe Cactus National Monument sits right against the Arizona-Mexico border in south-central Arizona. I was last there in 1993, before things along the border got really bad. I was able to do some hiking around in the backcountry and felt reasonably safe in a tent along the way. These days, all backcountry areas are closed to hiking and overnight camping. Supposedly, it's a temporary closure, but it's been temporarily closed for several years now. This is a problem that crops up anywhere there is a road on the American side that gets close to the border.
A major part of the National Monument is designated wilderness, and is "backcountry" by definition (and therefore closed to all legal access). That leaves some areas around the Kris Eggle Visitor Center than can be explored on foot, and the North Puerto Blanco scenic drive, a 2.5-mile route with interpretive signage and several scenic overlooks along the way. There's also the 21-mile Ajo Mountain scenic drive with hiking trails and picnic areas along the route.
El Camino del Diablo Back Country Byway runs west from Organ Pipe along the border. It's a beautiful drive across a horrible "road" in stark, barren desert but you'll need explicit governmental permission before you try to drive it. To the east is the Tohono O'odham Reservation, to the north and west Cabeza Prieta National Wildlife Refuge.
Winter and spring are the busy seasons at Organ Pipe. The colder days tend to be cool but there's no snow or frost. And a wet winter leads to brilliant cactus flower displays in the spring and summer. Summer tends to be really hot in the Sonoran Desert, so I'd avoid hiking in the daytime if I could. Late July through September is monsoon season, and the thunderheads rising high in the sky can deliver some really dramatic cloudscapes.
The organ pipe cactus blooms mostly at night in May, June and July. To see the best blooms, be up and out early in the morning before the sun's rays get too hot and the flowers close for the day. Each flower blossoms for one night only.
There are 2 campgrounds in the National Monument: Twin Peaks and Alamo Canyon. Neither offers electricity or running water at each site but there is electric and running water in the bathrooms. Twin Peaks can take RV's up to 40' long and has some spaces just for tents. Alamo Canyon is 4 sites for tents only and requires reservations (at the Visitor Center).
A couple of natural arches at Organ Pipe Cactus National Monument
Organ Pipe Cactus National Monument area map