Jump off Hwy. 169 on an unmarked road between Shakopee and Jordan, and you can peek at what looks like a giant sandbox.
Trucks and cranes nose through sand piles on self-created roadlets, just like the ones every boy used to have at the age of 4 -- and from where you're sitting, they look about that size.
Much closer, though, is an item without the same cozy connotations: monitoring equipment that is helping determine whether all this mining could be endangering peoples' health.
Frac sand mining has drawn little fire in Scott County at a time when other counties in the state and in neighboring Wisconsin seem more wary. Now the state of Minnesota is stepping up its own level of caution.
Two state agencies are asking Winona County to order an in-depth study of environmental and health risks associated with mines and processing.
And a state toxicologist with a Ph.D. from Dartmouth College, when asked whether Scott County figures in those same concerns, responds with a yes.
"Each of the facilities that have been proposed are different, but air concerns are similar for all," said Hillary Carpenter of the Minnesota Department of Health. "We are concerned about potential ambient exposures from silica and from exhausts from trucks and on-site equipment."
But officials in Scott County say they were well aware in green-lighting the mining that the level of concern could rise later on and took steps to safeguard folks nearby.