See Star Tribune Metro Columnist Jon Tevlin's latest report on the frac sand boom:
http://www.startribune.com/local/188938201.html
Frac Activist Movement is Watchful and Growing
Citizen groups increasingly watchful of movements in the frac sand industry as investors, companies vy to gain a foothold
January 30, 2013 at 5:50PM
It’s too soon to tell how much the immigration crackdown is to blame.
