A desert hike through Joshua Tree with high tech
Finally, mercifully, the tilted sandbox levels off as it crosses the Upper Covington Flat Road, turning downhill past the perfectly named Eureka Peak. The zigzag horizon, the distant peaks of the San Bernardino range, has turned copper. I begin to notice my feet. They feel wet and gritty. Sand from the wash has shipped in over my boot collars.

Not far now. I switch on the Garmin to find my first way point, where I've cached a 2-gallon bag of water. The device's little floating arrow guides me to within 3 feet of the rock under which I hid it.

Exhausted, I set up my tent. After a nap and a dinner of re-hydrated beef stew, I call my wife on the Iridium sat-phone. I can't help myself. I miss her.

Stepping vigilantly

Day 2, Upper Covington Flat to Juniper Flats. I wake up at 5 a.m. and get on the trail about 6:30 a.m. I use duct tape to fasten my little solar panels to my backpack to power my iPod, which today is devoted to Jack Johnson. It's a perfect day, chilly and clear, with a stark wind out of the east, and as the trail comes to a breach in the boulders, I reach an overlook of the Covington Valley, a vast and shallow parabola of rusty rock and scorched cactus stretching to the northwest. It's going to be a good day.

Hours go by. Like other sustained-heart-rate aerobic exercises, backpacking releases neuro-hormones that, first, bring a rush of mental energy -- the brainstorms, flashes of insight and relived conversations that you mutter to yourself like a crazy person.

Then, the lull of repetition, the hypnosis of boots, the trance of the trail. Crunch crunch crunch. No talking now. This is the time of listening to your body. With every step, physical imperfections I've incurred over 48 years begin to assert themselves. The right foot I broke two years ago is beginning to ache, a slight singing pain. The small of my back, wrenched in the gym 10 years ago, is tightening up, no doubt because of my monstrously overloaded pack.

From the knife-edge ridges to the deep scrub of the flats, the trail is an endless cascade of loose rock and sandy chuckholes, a terrain tailored to roll an ankle or send a hiker sprawling toward a shattered patella. I consider every footfall carefully. The step-by-step vigilance is exhausting.

After 14.7 miles -- including a brutal side trip on the Stubbe Springs Loop Trail -- I come to my second cache, buried in the hole created by a toppled tree near Ryan campground. After I check in with my wife -- I promised, after all -- I collapse under a convenient rock shelter and dream of cactus.

To trust too much

Do backcountry electronics offer a false sense of security? ACR -- the maker of the Microfix locator beacon -- advises customers not to rely on the device to save them from their own overconfidence. Yet it seems inevitable that some users will go farther, turn around later, climb higher and generally bite off more adventure than they can chew, knowing they can call in the Marines if they need to.

I might be in this category. I have a fair amount of backcountry experience, but a six-day solo in the Mojave is an aggressive program. Would I try this without the deus ex machina in my backpack? I don't think so.

Too much trust could be dangerous. Yosemite search-and-rescue manager Keith Lober tells me GPS readings can be significantly corrupted by various kinds of atmospheric and electronic interference, so that, for instance, a locator beacon might give rescuers an area of 10 square miles to search. It can take hours to zero in on a signal.

To some extent, the beacon is the outdoor equivalent of the Medic-Alert thing they advertise on TV -- a high-tech solution for affluent adventurers old enough to be aware of their own mortality. And what if I did have a heart attack out here or threw a clot in my sun-scrambled brain? Would I even have the time, as I timbered to the ground, to flip the plastic guard on the locator beacon out of the way and hit the button, the button that says, "I've fallen and I can't get up"?

Battered feet

Day 3, Juniper Flats to Fried Liver Wash. After two days in the bush, this much is certain: My backpack is killing me. I cull my gear, ditching among other things my tent.

Before I break camp, I spend some time wrapping moleskin and bandages around my feet, which are starting to worry me. Then I check in with home again.

Of all the devices, the sat-phone is the hardest to justify in terms of the wilderness gestalt. Don't people come out here to get away from phones? Don't people want to set aside their obligations? As soon as I'm connected -- the transmission quality is better than that of my cellphone -- I feel myself being pulled away from the land, the sky, the moment. I have to find words again.

The unexpected beauty of a sat-phone is not that everybody back home knows I'm OK, but that I know they're OK. It means I can keep playing.

As I shoulder my vastly lighter pack for the day's hike, I feel 10 feet tall. The conditions are exquisite. I storm across the paved road and pick up the trail, heading into a valley between buff-colored granite escarpments. This is the most magical region of the park, where hugely improbable granite boulder piles have bubbled up through the rolling desert floor in relatively recent geologic times. It's the only place on Earth quite like it. This is Flintstones territory.

Soon the landscape opens up stupendously and then, a little sun drunk, I seem to catch a glimpse of myself, as if from some distant mountaintop, a high-tech ant taking a meandering path through a terrain too big to see or grasp. The scrub is high and sharp here, the vistas surreal. A cool breeze dries the sweat on my face. This is peak experience, backcountry bliss.

More hiking. I have about 6 miles on the Garmin's odometer when my feet begin to throb. I eat some Advil. By the time I reach the Geology Tour Road, I'm limping. Two hours and 3 painful miles later, I reach my third water cache, where the trail for Hexahedron Mine snakes into the hills from Fried Liver Wash. I pry off my boots and my wet-with-sweat socks. My feet are bleeding. All of my toenails have worked themselves loose from their beds. Uh-oh.

Realization sets in

Sitting on a rock and using my waterproof jacket as a basin, I soak my swollen feet in cool water, but I soon realize I can't go on. After three days and 40 miles, end of story. I feel stupid. I pull on my boots and hobble the several miles up to Geology Tour Road, where I meet, of all things, geologists. I bum a ride with them to the main road.

Before I climb into the geologists' van, I pull out the sat-phone and call my wife. In a few hours, she'll pick me up, her gimpy adventurer. The nice thing about a sat-phone is that you have options short of a full-on rescue. Though I'm in definite distress, I doubt the search-and-rescue guys would have been pleased to find me suffering only from overtaxed, citified feet.

No rescue chopper for me, only a white Honda minivan.