Chemical spill into Mont. river spurs water watch - Article Photos 2/2

This photo provided by Hanser's Automotive shows pieces of two trailers that went into the Clarks Fork River near Belfry, Mont. on Monday, Feb. 11, 2013 spilling an estimated 7,000 gallons of magnesium chloride, a chemical used as road salt. (AP Photo/Hanser's Automotive)