To the west of this small town, which helped inspire Laura Ingalls Wilder's classic book series that included Little House on the Prairie, the view opens to a vast, unbroken landscape that seems to roll on forever.
But this untamed vista is shrinking.
The USA's open plains and prairies are threatened by soaring grain prices that have increased their value as cropland. Grain prices have been driven up by a seemingly insatiable worldwide appetite for food and by federal energy policies promoting corn-based ethanol that are working at cross purposes with government programs designed to conserve open spaces.
As a result, landowners in South Dakota and across the USA's Farm Belt are converting to cropland marginally productive acres that for decades — in some cases, centuries — have remained uncultivated because farming them wouldn't have been profitable or because of their environmental value.
"We're kind of in an ag revolution," says Bill Wilkinson, a farmer-rancher near De Smet.
Leaving at least some land idle amid the increasingly industrialized business of farming is essential for a variety of reasons. It provides a cleansing buffer for the water that runs off chemically treated fields. Protection of fragile wetlands cuts soil erosion while providing wildlife habitat that, in South Dakota, is the basis of a multimillion-dollar hunting and tourism industry. Native grasslands sustain biological diversity that can't be replicated. Further, plowing untouched prairie releases carbon dioxide into the air, contributing to climate change.
Long-term benefits are being overtaken by short-term incentives, however. Farmers chasing near-record prices are coaxing higher yields from current acres and putting more land into crops.
Kevin Baloun, a farmer-rancher near Highmore, S.D., is among them. He's plowed up several pieces of virgin prairie in recent years to plant crops. Land values in his area have tripled in the past five years, which makes it harder for farmers to expand production by buying more cropland.
"The bottom line is what makes you go that direction," Baloun says of his conversion of prairie to cropland. "Wheat was $4 or $5 a bushel a couple of years ago, and now it's up to $10 or $12 a bushel."
Conservationists warn that the current commodity and ethanol frenzy could undo years of hard work and undercut the investment of taxpayer money that has bankrolled federal land- and water-protection programs.
"A generation of conservation accomplishments could be rolled back" if commodity prices remain near historic highs, warns Ken Cook, head of the non-profit Environmental Working Group.
The nation is in the midst of the biggest agricultural boom since the 1970s. U.S. net farm income is expected to hit a record $92.3 billion in 2008, more than 50% above the 10-year average. Grain prices have soared because of high demand in emerging economies such as China and India. In addition, Congress last year voted to double production of corn-based ethanol, a cleaner-burning fuel that can reduce greenhouse gas emissions.