I’m riding a sure-footed black and grey Appaloosa named Chip through a natural obstacle course of greasewood brush, rabbit holes and hummocks of stirrup-high yellow grass in southern Colorado’s San Luis Valley. Somewhere in this 20,230-hectare pasture on Zapata Ranch, where I’m staying, a herd of 2,500 bison is roaming. Ranch hand Dan Lorenz and I stand in our stirrups to scan the high desert plain that stretches towards more than 200-metre tall sand dunes swirling at the base of the 4,260m Sangre de Cristo Mountains. Before the US Civil War, North America’s wild bison numbered in the tens of millions, with individual herds so large that they kicked up dust clouds that could be seen for miles. Zapata bison tend to split up into sub-groups, and locating them is a bit like trying to find a needle in the proverbial haystack. Lorenz thinks we may find a few grazing beside a marsh fed by mountain snowmelt. We turn to follow the yips of coyote pups hidden deep in the grass, hoping they may be hunting rodents that passing bison hooves stir up. Wild bison once ranged over a fenceless prairie that stretched from Texas to Canada and from Minnesota to Colorado, Dan tells me. After the Civil War, the US government encouraged an all-out slaughter to open up grazing for cattle and to force nomadic tribes that relied on bison hunting onto reservations. By 1883, bison had become so scarce that when US president Theodore Roosevelt went to the South Dakota Badlands to hunt a trophy bull, trackers couldn’t find one for him to shoot. Roosevelt, a conservationist and big game hunter, spearheaded a programme to capture and breed 88 of the last remaining animals, bringing the population back from the brink. But today, apart from the 3,000 or so roaming Yellowstone National Park, the vast majority of the nation’s 500,000 bison are raised for meat. In the 1990s, bison were reintroduced on Zapata Ranch by a Japanese investor who wanted to sell the meat for profit and turn part of the 41,680-hectare former cattle ranch into a convention centre and golf resort. In 1999, Zapata was purchased by Nature Conservancy, a non-profit organisation that has obtained conservation easements on millions of hectares of private ranchland to prevent subdivision and the extraction of water and minerals for industry. The golf-course idea was abandoned, old stables and bunk houses were conserved and, to diversify income, the ranch launched a guest programme and diverted half its land to raising beef cattle. The US frontier was ever a balancing act between old ways and the new, and Zapata has joined the ranks of progressive ranches across the west attempting to marry tourism and conservation, looking beyond dude ranch clichés and the beef industry’s obsession with carcass yields and USDA grades towards the holistic state of the range. For most of the year Zapata’s bison roam free, a breathtaking if melancholy sight for guests, 60 per cent of whom come from overseas to ride horses on what is the equivalent of an American Serengeti. Though much has been irretrievably lost over the past 150 years, the habitat manages to support 500 plant, bird and animal species, including bobcats, endangered sandhill cranes and even the occasional cougar. But the operation can’t survive on visitor fees alone, so each October, Dan tells me, the bison herd is rounded up and two-year old bulls and non-pregnant cows are culled for their low-fat, grass-fed gourmet meat. I’ve seen bison before, from a car in Yellowstone National Park. So I’m surprised when a first glimpse of about 80 bison cows and their shaggy yearling calves, a dark line moving along the edge of a slender, spider flower meadow, makes my heart catch in my throat. It’s September. Summer rain is infrequent and the big-headed creatures appear startled by a sudden spectacle of lightning, rain sheets and brilliant sun shafts alternating between towering grey clouds. The skittish herd stampedes in a rumbling crescendo of footfalls whose vibrations pass from the earth through Chip’s body and up into my bones. Dan has warned me that bison are faster and more agile than horses, but they are also curious. Spying us, they stop to sniff the wind, whirl and flee, only to change their minds and run back towards us. The bison settle, sunshine prevails and Dan and I rest our mounts, unpacking a saddle-bag picnic beneath a cottonwood tree. Nearby is a clearing where Zebulon Pike camped in 1807 during his mission for Thomas Jefferson to map the western boundary between the Spanish Territories and the Louisiana Purchase. Back at the ranch headquarters, before a dinner of marinated bison T-bone – richer, if slightly chewier, than beef – I watch a red hawk wheeling and mule deer grazing outside my chinked-log bunkhouse. What goes around comes around. Turns out I’m standing just a few hundred metres from a site where archaeologists have found stone axes of Paleo-Indian people who butchered prehistoric bison 11,000 years ago. Zapata’s first stakeholders were Mexican sheep-herders settling what had originally been Jicarilla Apache and Southern Ute Indian bison-hunting territory. After the San Luis Valley became part of the United States in 1848, Texas cattlemen moved in; the ranch has since passed through many hands, reflecting cycles of cattle booms and busts and unpredictable agricultural conditions that have forced ranching families to either sell their land or take in paying guests to sustain a classically American way of life. A fifth-generation Colorado ranch family currently manages Zapata’s beef cattle. Unlike guest programmes that can seem more boutique resort than ranch, Zapata has no health club spa and neither does it offer a kids’ programme, staged barn dances or cowboy singalongs. Visitors like me stay in a collection of 19th-century log buildings and take communal meals in the original main house. In addition to rides with the bison, there are guided hikes, camping trips and horseback rides through the dunes and nearby mountain forests. But the biggest draw for many guests is the chance to experience the daily ranch routine and perform authentic cowboy work, whether it’s mending barbed wired fences in the rain or gathering cattle on horseback for six hours straight. The next day I join the other guests, a couple from San Francisco and two women from France, tasked with three ranch hands to move 850 beef calves and their mothers from a section known as Antelope Pasture to fresh grass on a pasture called Break Tree. Dan Lorenz draws a map in the dirt showing groups of cattle, water holes and fence lines. We mount up and after riding past the ranch outbuildings split into three groups, each accompanied by a staff cowboy, to search for pairs of cow and calf. Though I was raised in Chicago, the valley before me feels strangely familiar. Sunbeams shoot halos behind fat cattle ears; yellow rabbit grass sways beneath rivers of wind; and I’m channelling Bonanza episodes, Willa Cather novels, the Terrence Malick film Days of Heaven and an urban childhood spent yearning for a horse. Instead of cracking bullwhips, yelling, throwing rocks and other old fashioned methods, Zapata cowboys practise a new-agey round up technique called “natural stockmanship”. Like wild plains game, cattle are instinctively wary of predators shadowing the herd. The idea is to ride your horse close enough to a cow to make her look up and start walking without spooking her into running, which burns up calories and weight. Instead of being allowed to graze freely, cattle are walked to new grass every few days. “It’s better for the land and better for the cattle,” says ranch manager Regin Fletcher. This “rotational grazing” not only optimises cattle weight by providing the freshest pasture but also mimics bison migration, which gave tip-sprouting prairie grasses a chance to rest, preserving the ability of soil to transform sunlight, water and carbon dioxide into life. With Chip’s cow sense, I soon get the hang of “pushing” cattle, as the cowboys call it, and gather strays, trading places along the herd line with the other riders. There’s no lunch break. When I get hungry I munch a beef sandwich with an ibuprofen chaser from my saddle bag. The guests are all experienced horsemen and women, but there’s less galloping across the sage than I expected. The goal is to conserve energy, not just of cattle, but horses, people and the hardest workers of all, Zapata’s fleet-footed Australian and Scottish herd dogs Elvira, Hector, Maya and Poke. Two hours later we all converge at a gate where a cowboy named Jeff carefully counts cattle – 841 cows and calves in all. “I actually count everything that goes through the gate – cows, horses, dogs, people – and subtract the non cattle after or else I get mixed up,” he says of his system. “I even counted a butterfly once.” Cattle in the US now number 94 million and have long since replaced bison in the ecosystem. But rather than exclude wildlife and degrade the land through overgrazing or be fattened on corporate feedlots on corn, growth hormones and antibiotics, we’re learning that at least some cattle today are being raised in humane circumstances, both for profit and to sustain diverse species in a near-pristine natural environment. Ranchers and conservationists have often regarded one another with suspicion – ranchers are typecast as bad guys, heedless of the natural ecology, while conservationists are seen as softies who love wildlife more than people. But attitudes are changing as both sides realise that the Old West can be preserved and urban development held at bay by a healthy cattle range that also creates space for wildlife. This natural cycle includes the elk and mule deer that follow both bison and cattle to graze on their stubble; their sharp hooves aerate the soil, enabling it to hold moisture and stop erosion. At Zapata Ranch, the landscape also includes travellers who, in riding the open range, become part of the big picture. <strong>The flight </strong>Return flights with Etihad Airways (<a href="http://www.etihadairways.com">www.etihadairways.com</a>) from Abu Dhabi to Denver via Chicago cost from Dh5,710, including taxes. <strong>The stay <span style="font-weight: normal;">A three-night (minimum) stay at Zapata Ranch (<a href="http://www.zranch.org">www.zranch.org</a>; 00 1 719 378 2356; open from March until October), including meals and horsemanship, costs $985 (Dh3,618) per person. Five- to seven-night packages include riding clinics and ranch work. Advanced riders can sign on for the annual bison round-up in October.</span></strong> <strong>The info <span style="font-weight: normal;">Zapata Ranch is a three-hour car drive from Colorado Springs. Pick up a can of Fix-o-Flat, a spray-on tyre repair kit, from a gas station in case of a blow out on remote gravel roads.</span></strong> <em><strong><span style="font-weight: normal;">This article has been altered to reflect that </span></strong>3,000 or so bison are roaming Yellowstone National Park, not 20,000 as originally published.</em>