WINONA, MINN. - Three years ago, a Texas businessman named Kim Smith landed in this little river town by chance, when his private plane ran low on gas.
As he approached the runway, the distinctive bluffs and railroad tracks that embrace the Mississippi River spread out before him. Below, on the west end of Winona's sprawling industrial riverfront, rose tall piles of gravel and sand.
Today, that confluence of river, railroad and Texas entrepreneurial spirit has made Winona the epicenter of a new Midwestern gold rush: frac sand mining.
Nearly 50 mining operations have opened nearby in the past few years, producing enough sand to send 54,000 semitrailer trucks rumbling down Winona's main street in a year.
But as the boom spreads, from western Wisconsin to Mankato to Shakopee, it is igniting a debate over sand mining and the larger industry it serves -- the controversial oil and gas drilling practice called hydro-fracking.
Just last month, dozens of Winona residents took to the street near the heart of downtown, waving protest signs in front of a 50,000-ton pile of sand they derisively call Mount Frac. "Short-term profit, long-term problems," read one placard.
But many in the industry say sand mining is here to stay, as long as oil and gas companies continue to ramp up domestic production to address the nation's energy demands.
"When gas prices get to $7 per gallon, maybe they will say that fracking isn't so bad," said Smith, the head of Sierra Frac Sand, a small Texas player in the national industry.