Rem Hawes doesn't wear hiking boots. The Agua Fria National Monument manager had on what you might expect of a government fireboss: worn leather boots with flashing at the toe. At the younger side of middle age, he was fit and trim, a long-range hiker.

We drove out together one February day from Phoenix with Scott Jones, the Southwest director for the Conservation Lands Foundation, a nonprofit dedicated solely to bolstering BLM's national conservation lands, including Agua Fria. After an hour's drive north from Phoenix on I-17, we took an exit where the freeway cut up to the top of a black basalt mesa and drove east into the monument. The road turned to dirt right away and we bounced in a Jeep across the ruts and ditches of bouldery grasslands.

"The monument has a hundred miles of drivable roads," Hawes said from behind the wheel. "Seven miles are graded."

That was a boast. The dwindling arteries of roads in the monument help spread people out, he explained, rather than drawing them to a single place. The monument has no center, no viewpoint, no ramada at the end of the road with a lonely row of picnic tables waiting just for you. It is wide-open, challenging country -- what makes the West unique.

"There are some places your classic visitor can go here," Hawes continued. "You can look on a map and find a destination, but the bigger purpose here is that the landscape itself is a destination. Where is the one waterfall everyone's supposed to see? Where are the geysers? This isn't that kind of place."

"It's not the Devils Tower experience," Jones added.

Ruts turned to naked boulders and dust, and Hawes downshifted into 4-low. We parked at an unmarked spot near towering metal pylons and then got out with daypacks. I peered up the tight sway of high-tension power lines that cut across the middle of the monument. Walking under and past them, we could hear the hum and crackle of electricity high overhead. I thought, This isn't wilderness.

The power lines, Hawes pointed out, are part of what protects Agua Fria's sense of solitude.

He gestured toward the barely discernable motion of semi-trucks six miles off, visible through a gap in the rolling dry grass and agave stalks. "I-17 on one side and the power lines on the other form a boundary, and people really don't think about what's in between."

Tiers of half-mile-wide canyons carve down through the mesa's edge where we walked. You wouldn't see them unless you stood at their edges. Palisades and steep boulder fields led to garlands of cottonwood and sycamore, some of the canyons running with streams or at least prosperous springs.

Like Gold Butte, Agua Fria takes in a big sweep of land, in this case most of a mesa 10 miles long and six miles wide, crowned with high-desert caprock, and wreathed at the base by the Agua Fria River, where clear, cool water flows beneath tall saguaros, carving the mesa's southern edge into steep, rugged drops.

Jones and I followed Hawes down a flood-polished channel of basalt, ducking around spiny mesquites. Barrel cacti grew among agaves and black, bubbled boulders. "Right up here you start seeing them," Hawes said.

At first, we found simple etchings on boulders, stick figures and rectilinear designs. Then we saw hundreds of delicately pecked images of animals, people and great, interwoven spirals on flat walls of basalt outcrops. We were in the thick of the 11th century, the Perry Mesa culture, ancient Puebloan people living in the high desert of central Arizona. You'd expect the ground here to be beaten smooth by visitors, little arteries breaking away to view each rock art panel. But there were no trails at all.

As we explored the galleries of rock art, hopping from boulder to boulder, we encountered a fat, dust-colored rattlesnake. It barely buzzed, lazy with the morning. We crouched and watched it slowly glide through the grass.

"It's locals' territory," Hawes later said, describing what national conservation lands tend to have in common. "The ranchers know this place -- the hikers, people on ATVs, horseback. Blue-collar sign-shooter ATV groups … are a major base for us."

The monument is loaded with four-wheeling opportunities, but much of it is accessible only to foot and horse. The Arizona Wilderness Coalition has recommended two wilderness study areas here, totaling 28,667 acres that would seal off the more remote country.

At a gap, we climbed up through caprock to the smooth mesa top. On this higher, wind-blown sweep, the ground was littered with broken pottery, sherds dating back several centuries, in some places so thick you could scarcely avoid stepping on them. Early agriculturists once lived here, pueblo-dwellers, corn and agave growers. Calling to each other, bending down and picking up design-painted sherds to show each other, we slowly worked our way toward a rise. It turned out to be a rock-stack of ruins, an ancient pueblo at the mesa's edge. The depressions of old room-blocks and the checkerboard rise of mostly toppled walls took up nearly an acre. Hawes had been here before, though he hadn't remembered exactly where it was. Every time, he said, he has to find his way anew.

At the crumbled edge of this pre-Columbian citadel, we looked down stair-stepped cliffs and boulders into a canyon-bottom riparian zone a few hundred feet below. There were no trails. Hawes told me the place was not something you'd even pick up on the Internet as a destination, a canyon unnamed on most maps.

Below the ruin, we sat out of the wind. "Last day of freedom," Jones said to Hawes.

I asked what he meant and Hawes explained that he was taking a higher position within the BLM managing a bigger, more broken-up piece of desert outside Phoenix. No national conservation lands.

"Is this what you wanted to do on your last day?" I asked.

Hawes looked past his boots, propped on a boulder, to the canyon open beneath him, and laughed, "This is what I would do every day if I could."