'The Price of Sand' is a documentary film about the frac sand mining boom in Wisconsin, Iowa and Minnesota. A year ago, an oil company bought land next to my mother's house in rural Minnesota. The deal was kept secret for months, because the new owners wanted to build a huge open pit frac sand mine. When their plans became public, I started to investigate. Over the course of this 18-month project, I interviewed small town mayors, truck drivers, business owners, farmers, and two angry moms. I learned that pure silica sand is used for everything from toothpaste to window glass. And I found out that the price of frac sand can't be quoted in dollars and cents.—Anonymous