FRANKLIN MOUNTAINS, Texas — Two big rams bolted from the steel trailer, took a few hesitant steps and glanced around nervously at their new home: dramatic mountains in west Texas more than 200 miles from where they grew up. Within seconds of looking in all directions, they scrambled into the crevices of peaks that reach 7,000 feet above sea level. A knot of onlookers, more than 100, burst into cheers.

A victim of livestock disease, reckless hunting and the destruction of their Chihuahuan Desert habitat, these creatures vanished once from Texas. The last documented sighting of a native was in 1958 in the Sierra Diablo range to the southeast, and decades of conservation efforts followed with mixed success. But on a warm afternoon in December, 77 of these animals were captured near the town of Alpine and hauled back home to build a large wild herd — another chapter in the rewilding of the American West.

The desert bighorn, distinct from its Rocky Mountain cousin, ranges from the Chihuahuan Desert here to Utah, Nevada and the Mojave and peninsular deserts of California. The urbanized Texas landscape to which these megafauna return is vastly different from the one where they vanished decades ago. Restoring the natural balance in today’s West will involve humans, predators and other animals, a fragile balancing act that could be rich with reward.

I grew up in the city of El Paso and never saw a bighorn. Though I roamed the mountains of this region, often with my late father, I rarely glimpsed any endangered or threatened creatures, their numbers so small, their struggles for survival limited to the folds of mountains and arroyos. Yet in the last decade, I have seen mountain lions and bobcats in broad daylight and have caught the once nearly extinct Gila trout, slipping it alive and well back into its cold native waters. Now the bighorn was just a foot away.

The desert bighorn is legendary. The ancestors of Native Americans drew pictures of this keystone creature centuries ago in the Coso Range of California to the west and nearby in Three Rivers, N.M. This wild sheep was thought to be foundational to life in the desert: a spirit animal that guided predators, including humans, to food — often its own flesh — water and cover from the fierce Southwestern sun. But after Europeans arrived and expanded their westward settlements, especially in the 19th century, they loosed herds of cattle, horses and other livestock that competed with sheep for grazing while spreading disease.

In the 1950s, Texas began the painstaking process of redressing humans’ disruption of nature. Ovis canadensis nelsoni were imported from Nevada and raised on a private ranch near Alpine — right nearby, in Texas terms. Their numbers grew from fewer than 20 in the 1970s to more than 100 by the ’90s. Missteps occurred too: A herd transplanted near Van Horn was nearly wiped out by mountain lions, and bighorn have taken a hit from pneumonia spread by a rival sheep, the hardy and bearded aoudad, which carry the infection and are less affected by it. But the state rebuilt the bighorn population to about 1,500. Today, around 20,000 of them are scattered across the wilds from west Texas to the Mojave.

These animals are big, about the size of a mule deer, with some males weighing over 150 pounds. They’re also tough: What water they do get normally comes from their steady diet of desert plants, including cacti and other succulents. Herds can go long periods without water, which allows them to stay in places predators cannot follow. They can become dangerously dehydrated but recover quickly when they finally find a hidden desert seep. In west Texas, they will be tempted to explore the desert public lands to the north and northeast. Wary, with laser-sharp eyesight, they often stand hindquarter to hindquarter facing different directions on the lookout for coyotes and mountain lions.

A recent camera survey by the Texas Parks and Wildlife Department didn’t spot any mountain lions in the Franklin Range, a department mammalogist, Dana Karelus, told me. Yet the occasional lion does roam here; in the last 15 years these big cats have been sighted in El Paso near a car wash, in a neighborhood and inside the city zoo.

But a stray ewe or a wobbly lamb makes a far bigger meal than, say, a house cat. The presence of the bighorns, then, is likely to draw lions toward the mountains instead of the city, where their visits are already rare. Coyotes adapted to urban environments may venture back into the mountains during lambing season. Omnivorous bears occasionally wander here too and will be enticed by a big meal, even a carcass, as long as it doesn’t take too much work. “It is a delicate balance in the case of urban areas,” Karelus told me.

Humans might glimpse these wild sheep when they venture onto the 100 miles of trails crisscrossing the 27,000 acres of Franklin Mountains State Park. And they should keep a lookout, especially in the deep nights of winter, on Texas Loop 375, a busy highway that cuts east to west. On the day of the bighorns’ release, highway signs flashed: “WATCH FOR WILDLIFE.”

“We fully expect them to stay up high,” Texas Parks and Wildlife Department Director David Yoskowitz said. “They want to stay away from humans. We feel very confident, we just have to respect each other’s space.”

The desert bighorn is bumping into other man-made obstacles across the Southwest. Nevada has built the most robust population through dedicated conservation efforts. But Southern California’s wild sheep are hemmed into small islands surrounded by oceans of city. Their survival and expansion depend upon corridors of travel from one group to another to promote the genetic diversity needed for adaptation. One California herd has actually grown in the Angeles National Forest because of a landslide decades ago in the San Gabriel Mountains that severed more than four miles of State Highway 39, according to California Department of Fish and Wildlife biologist Rebecca Barboza. With the road since closed to all but emergency vehicles, the bighorn ewes have had unimpeded access to prime lambing ground, plentiful forage and water.

“Without humans around, they really thrive,” Barboza said. “The forest is an island. These animals need to spread out — or die.”

In today’s urbanized Southwest, much as the animals will have to adapt, humans have to learn to share space with these homecoming creatures. In the Franklin Mountains’ new bighorn herd, it turns out half the ewes are pregnant: A new generation of lambs is due this spring.

Watching the bighorn run, I heard something I didn’t expect: silence. Their uniquely rubbery hooves made nary a sound as they darted toward the purple peaks. And in the fading light, the desert bighorn reappeared and disappeared all at once into the gathering winter dusk.

Richard Parker wrote this essay for The Times over the winter. A longtime journalist, commentary writer and author, his latest book, “The Crossing: El Paso, the Southwest and America’s Forgotten Origin Story,” was published March 4. Parker died earlier this month.