"Can we get to the Pecos River on this road?"

"Yep."

"How far is it?"

"A few miles."

"Is there a bridge?"

"Yep."

"Oh, we’ll turn around and get the car."

"You broke down?"

"No, we’re just river tracing."

What the crusty, old man in the battered pick-up didn’t warn us: Several miles down the caliche road was a steel gate that barred our way. After we turned around, a younger, grimmer man, also in a pick-up, grilled us on why we took this isolated road and how we found out about it anyway.

Our weak response: "It’s on the map."

Flash to "No Country for Old Men."

The final sixty miles of the Pecos River, the 29th in our series of Texas river tracings, runs through steep canyons that crease the otherwise thrillingly desolate landscape. If there’s a bridge between Texas 290 at Fort Lancaster and the Pecos High Bridge at Lake Amistad, we didn’t find it.

As we track 50 Texas rivers by car, on foot and occasionally by water, we like to follow the course from the source to the mouth. In this case, the Pecos rises in the mountains near Santa Fe, so we settled for the closest point near the Texas border, beneath the Guadalupe Mountains in Carlsbad, N.M.

There, amid the rampant oil-and-gas fracking boom, we found overpriced fauxtel rooms ($250 with tax!) and hearty food (green chili cheeseburgers at Yellow Brix, $12) along with affordable attractions of global rank (Carlsbad Caverns, $10), regional wonder (exquisitely landscaped Living Desert State Park zoo and botanical gardens, $5) and local value (Pecos River Park, free).

Here, the river is dammed and used for rural and urban needs. The evolving city park, explored on an icy morning, includes a quaint shopping village, power-plant-turned-recreation-center, a light pontoon bridge and plenty of fishing. (Signs request the return of working grass carp to the system.)

On the Texas side of the border, we picked up the Pecos near Mentone, the seat of sparsely settled Loving County (population: 82). So little has happened here, the centennial stone historical marker in front of the courthouse ends in an incomplete sentence. Here, the shallow river winds among the sandy hills playing peek-a-boo with the traveler, sometimes disappearing altogether.

The Pecos reappears when it spills down onto limestone ledges amid the austere mesas to the south, near the thriving towns of McCamey and Iraan, high school football centers that could double for Dillon in "Friday Night Lights."

The namesake city of Pecos is a dusty, yet fast-growing crossroads in transition, formerly known for cantelopes, now as a fracking supply center. The West of the Pecos museum, built into a former saloon and hotel, was not open during our visit.

Our second night was spent where all roads in this region lead: Fort Stockton. We dined on thickly sauced asado at Alfredo’s, an old Mexican restuarant with family appeal. (At all our stops, the beef, not surpringly, was excellent.)

Along the way, we ecountered multiple historical markers telling the story of the Butterfield Overland Mail route, which snaked through this region.

Fort Lancaster, however, protected the old San Antonio-San Diego road. Once on the main route west, the carefully maintained stone and adobe military ruins sit above Texas 290, a road so untraveled, we stood for as long as we wanted on the old tressle bridge over the Pecos, documenting flora and fauna alongside the wide, clear stream.

Our "No Country" adventure took place off lonely Texas 349, which crosses many dry, steep draws and leads to even lonelier FM 3166. Here, we passed right through a mysteriously unmarked chemical plant, then headed down a steep road to the narrow, green Pecos valley.

As everywhere in the Chihuahuan Desert, the presence of water promises a rush of wildlife. Earlier, we had startled small flocks of teals, buffleheads and shovelers, along with solitary great blue herons and great egrets.

We might have had better luck on this stretch of the river, however, tracing the east side of the canyon, but many of these Trans-Pecos backroads require four-wheel drive at some point, a option we did not have on this trip.

Instead, we wheeled through sad-sack Comstock and touristy Langtry (regular gas, $4.50 a gallon) along U.S. 90 till we reached the famed High Bridge. Draped in history, the various bridges over this breathtaking canyon provided a crucial link from East to West along the U.S. border. Now, multiple look-outs and river access make it a photographic prize at the point where the Pecos joins the Rio Grande as part of Lake Amistad.

As the sun drooped for a long desert setting, we headed to Del Rio, for we were set to investigate the pristine and even more isolated Devils River the next morning.