HIGHMORE, S.D. -- Bruce Roseland runs cattle here in the heart of the South Dakota grasslands, in the same place where his great-grandfather ranched more than a hundred years ago. But today, when he looks out his kitchen window, the prairie that once reached from horizon to horizon is gone.
Instead, he sees neat rows of corn marching up to the edge of the blue sky, growing where not too long ago it never grew at all.
"Did we ask the Indians' permission to come out here and destroy their way of life?" said Roseland, who will be the last of the men in his family with the gnarled hands of a rancher. "Well, that's what's happening to us. Except it's technology."
The 10,000-year-old native prairie that once stretched from Saskatchewan to the Gulf of Mexico has become one of the most threatened ecosystems on Earth -- more so even than the world's tropical rain forests, ecologists say. In Minnesota and elsewhere, only about 1 percent of the original prairie now lies untouched, and every year across the Great Plains millions more acres of grasslands are turned into corn, soybeans and other crops.
This hastening transformation is being propelled by a perfect alignment of forces -- rising global demand for food and energy, advances in farm technology and, some say, federal policies that take the risk out of farming marginal lands.
Together, those forces are giving a boost to an otherwise lackluster economy, especially in the rural Midwest.
But conservationists say the country is facing the loss of a national heritage and an irreplaceable ecological resource.
These biologically rich grasslands and wetlands cleanse the water of great river basins, reduce the pace of global warming and support a web of life that includes thousands of unique plants, birds and other animals. In Minnesota, that concern has prompted a coalition of state and conservation leaders to launch an ambitious, $3.5 billion project to restore some of the rare grasslands the state has lost over the last century.