Burlington Northern eastbound manifest freight train crossing the trestle over the Sheyenne River at Valley City, North Dakota on March 14, 1981.

Burlington Northern 6799 leading coal train on Stone Arch Bridge in Minneapolis, Minnesota on June 2, 1981. Number 6799 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 776053-9. Photo by Al Christianson.

Burlington Northern 6799 leading coal train on Stone Arch Bridge in Minneapolis, Minnesota on June 4, 1981. Number 6799 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 776053-9. Photo by Al Christianson.

Burlington Northern 6799 leading coal train on Stone Arch Bridge in Minneapolis, Minnesota on June 4, 1981. Number 6799 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 776053-9. Photo by Al Christianson.

Burlington Northern 6779 leading train on Stone Arch Bridge in Minneapolis, Minnesota on October 14, 1980. Number 6779 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 766024-7. Photo by Al Christianson.

Burlington Northern 6776 leading train in Minneapolis, Minnesota on October 23, 1980. Number 6776 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 766024-4. Photo by Al Christianson.