A sea of grassland waves under a clear sky, Bohart Ranch

The high grassland of Colorado is half a world away from Mongolia's Gobi Desert, but it offers a lesson in how to manage that fragile ecosystem. The fabled desert has doubled in size since 1950, due to forces such as climate change and overgrazing. Mongolian scientists are now partnering with U.S. conservationists to reverse the trend.

Grazing cattle dot a sandy landscape held in place by deep-rooted shortgrass prairie plants like bunchgrass, yucca and soap weed. Unlike most other ranches here, which have been subdivided into smaller tracts and developments, the Bohart Ranch near Colorado Springs stretches as far as the eye can see. The ranch itself has become a testing ground for techniques for running a working cattle operation while protecting fragile land. During droughts, for example, ranch managers don't graze as many cattle. This reduces their profits for that season, but the long-term data being gathered here indicate that the respite helps the sandsage prairie survive the dry weather.

Horned toad

As a small group of American and visiting Mongolian scientists enjoy the panorama, one spots a palm-sized creature hopping between two clumps of prairie grass, and pounces on it with a triumphant cry of "Horny toad!" U.S. biologist Steve Kettler shows the baby toad to N. Sarantuya, who directs the Environmental Initiative Center at Ulaanbaator, the capital of Mongolia.

"What is Latin name, the species?" she asks. As he plops the creature into her hands, he admits he doesn't know, and suggests Texas horned lizard as a more accurate name. Sarantuya laughs as she looks at the toad, "We have [a toad like this in the] Gobi desert, its Mongolian name is guroot."

N. Sarantuya directs Mongolia's Environmental Initiative Center

It's not just the toads of Bohart Ranch that remind Sarantuya of Mongolia. It's the vast sandsage prairie itself. For 2,000 years, Mongolian herders constantly moved their sheep, cows, yaks and goats across the open grasslands. They followed time-honored practices that minimized overgrazing.

Forty percent of Mongolians are still nomadic herders, but Sarantuya says that these days, mining, oil and gas development are displacing their pastureland. And because of changes in property laws, herders have doubled and tripled their flocks, to 27 million animals. "Today around 70 percent of Mongolian pasture is degraded to a certain level," she says. "Because of the privatization of the livestock in 1990, the number of livestock increased dramatically, and it was big pressure for the pasture, and we faced problems with overgrazing and sand movement."

That sand movement is of special concern. Dust storms, which can blow off millions of tons of topsoil in a single day, have turned many pastures into desert. Occasionally, the storms shut down airports and businesses hundreds of miles away. Some Chinese government experts estimate the livelihoods of 400 million people -- 30% of the population -- are threatened by desertification.

Cattle graze on the Bohart Ranch

One way to reverse this trend is to protect just the most important pockets of land. "We call it 'conservation by design,'" says Frogard Ryan. She works for the Nature Conservancy, which has helped preserve Bohart Ranch. "And some of our scientists have traveled to Mongolia to teach scientists there how we really go about that." She explains that by monitoring the density of native grass, how well the soil retains water, where sand is moving and other markers of habitat health, scientists can suggest which areas should be protected, which can be used for grazing, and which to develop.

Sandra Tanner, a member of the family that manages the Bohart Ranch, says she's glad the lessons learned in Colorado can help people in other parts of the world. "We're having an international exchange of ideas, and what we're finding is all these countries are experiencing very similar problems with population growth and development, and trying to preserve the resources without keeping them away from the population."

Tanner observes that it's always a balance, protecting natural resources, while making a living. N. Sarantuya reminds everyone of what can happen if the balance is upset. "Lots of sand!" she laughs, recalling visits to herding families in Mongolia. "When we're traveling and we visit a herder's family, and they … cook us soup, and in soup, we find, soup with sand!"

Through a scientific collaboration with the Nature Conservancy, the Mongolian government is working to increase protected areas in its national parks from 13 to 30 percent, in order to reduce the march of desert across the pastures of Mongolia.