For more information: Great Sand Dunes National Park, 719-378-6395, www.nps.gov/grsa; Alamosa Convention & Visitors Bureau, 800-258-7597, www.alamosa.org; Zapata Ranch, 719-378-2356, www.zranch.org. Room rates at Zapata Ranch are $1,380 per person for three nights; $2,530 per person for seven nights (all-inclusive).

Any romantic notion I might have had comparing myself to Lawrence of Arabia was rapidly fading as the spongy ridge of sand leading to the summit of Star Dune at Great Sand Dunes National Park in southern Colorado became steeper. Much steeper.

You probably know how it is to walk on a soft, sandy beach. Just imagine doing it on a beach tilted upward at an alarming angle — like a staircase. Sweating and gasping for breath, I realized why park rangers urge visitors to wear wide-brim hats, sunscreen, and to carry plenty of water. Temperatures were moderate during my early-morning hike last July — but the dune surface routinely reaches 140 degrees on summer afternoons.

The park’s 30 square miles of shifting sand comprise the nation’s largest inland dune field. Finally reaching the 750-foot summit of Star Dune, I was rewarded with a spectacular view of the towering, snow-capped Sangre de Cristo Mountains rising nearly 14,000 feet nearby, and the sprawling San Luis Valley below.

San Luis Valley is often called the “Cradle of Colorado.” It is a high-altitude desert, although its fertile floor is dotted with marshlands, springs and lakes — popular rest stops each spring and fall for thousands of migrating sandhill cranes and Canada geese.

Running through the valley is enchanting Los Caminos Antiguos Scenic & Historic Byway (Spanish for “The Ancient Roads”). The byway follows in the footsteps of Spanish explorers and Mexican settlers, Utes and Navajos, miners and ranchers.

A friend and I began a tour of the byway on U.S. Highway 285 in the village of Conejos, where we stopped for a look at Our Lady of Guadalupe Church, a venerable old mission church that is home to the oldest Catholic parish (1858) in Colorado.

Turning east on Colorado Highway 142 at Romeo, we continued for a few miles to Manassa, home to the legendary heavyweight boxing champion, Jack Dempsey. Known as the “Manassa Mauler,” Dempsey is memorialized with a bronze statue outside the modest cabin where he was born and that now houses the Jack Dempsey Museum. Sports fans will enjoy perusing the museum’s collection of memorabilia relating to the slugger’s illustrious career, during which he held the world heavyweight title from 1919-1926.

About a dozen miles east of Manassa we came to the Rio Grande River and the scene of the so-called Vargas Crossing. As the story goes, back in 1694, Don Diego de Vargas, governor-general of New Mexico, led a band of Spanish soldiers north into the San Luis Valley to escape a Pueblo Indian uprising. The Spaniards crossed the river at a point near the current Highway 142 bridge. In pioneer times this became the site of the heavily used Costilla Ferry.

Continuing eastward, we soon found ourselves in the state’s oldest town, San Luis, founded by Mexican settlers in 1851. There’s not much to the town itself — a cluster of wooden and adobe houses and stores (including Colorado’s oldest grocery) around a dusty square — but it is the site of perhaps the most important cultural attraction along the byway route. High atop a mesa overlooking San Luis is the Shrine of the Stations of the Cross.

A series of powerful bronze sculptures by Huberto Maestas are set along a half-mile path that ascends the mesa, depicting the stations of the cross from Jesus’ journey up Cavalry Hill. Atop the mesa sits the exquisite Capilla de Todos los Santos (All Saints Chapel), in a setting strikingly reminiscent of Spain’s Andalusia countryside. The shrine is a prime example of Christian devotional art found in Hispanic settlements throughout the Valley.

Northbound now on Highway 159, our next stop was Fort Garland, a partially re-created 1858 adobe garrison once commanded by Kit Carson. Now a museum, the fort is filled with items of the time, including firearms, uniforms and Native American artifacts. Visitors can explore the garrison individually or join a docent-guided tour.

Approaching the northernmost reaches of Los Caminos Antiguos on U.S. 160/Colorado 150, we paused to watch wranglers from historic Zapata Ranch ride herd on some cattle right beside the highway. This 103,000-acre spread is both a National Historic Site and a property of the Nature Conservancy. It remains a working ranch but offers 15 guest rooms in three different buildings, including the main lodge and bunkhouse, where we were able to secure a room for the night owing to a cancellation. Normally a 3-day minimum stay is required.

Guests can take part in a variety of outdoor/nature programs. Hiking trails and horse-drawn wagons lead visitors out to view the bison, elk, antelope, coyote and migrating waterfowl that coexist here in what has been described as the “Rocky Mountain Serengeti.”

Not far from the ranch (between mile marker 10-11 on Colorado 150) a short but steep trail leads up along Zapata Creek to Zapata Falls, an impressive cataract embraced by a pinon-juniper forest. A picnic area affords panoramic views of the valley floor and the nearby sand dunes.

Next morning I made my heroic dune climb while my less energetic companion stayed behind to dawdle in Medano Creek, an amazing stream made up of snow melt from surrounding mountains, that flows along the base of the dunes during spring and the early summer months.

Our final day of touring led us about 15 miles west of the park on Country Lane 6 to Mosca, where we turned south on Colorado 17 for the short drive to Alamosa. With a population just shy of 10,000, Alamosa is the largest city on the byway. It’s a lively place at the center of a large ranching and farming community and home as well to Adams State College. We did a bit of window-shopping, then tackled some green chiles rellenos at Cavillo’s on Main Street.

Before heading home we drove out U.S. 160 a few miles southeast of town to have a look at the Alamosa National Wildlife Refuge. One of three national wildlife reserves in the San Luis Valley, this one protects 11,000 acres of Rio Grande wetlands. We followed the auto tour route through a portion of the refuge, hopping out now and then for photos and wildlife spotting. We saw some ibis, egret and a variety of songbirds — plus a wily coyote —that turned up (no surprise) just as we were breaking out a snack.