Near Perham, MN, a westbound train of empty tank cars takes a curve on BNSF’s Staples Subdivision, the former NP main line between the Twin Cities and Fargo.  BNSF’s principal route across MN (and part of the Chicago-Seattle main line), the Staples Sub. is extremely busy with intermodal, coal, grain, and mixed freight.  In recent years, traffic has significantly increased with the “oil boom” in northwestern ND.  Of the 33 trains we saw this day (July 28, 2013), 8 or 10 were unit tank car consists. (Photo by Scott Wartchow, submitted by Fred Ripley)