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.

Burlington Northern 6770 leading coal train in Fridley, Minnesota on June 4, 1981. Number 6770 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 766010-18. Photo by Al Christianson.

Burlington Northern 6735 leading coal train in Saint Paul, Minnesota on May 1, 1981. Number 6735 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 756072-28. Photo by Al Christianson.

Burlington Northern 6735 leading a coal train on May 1, 1981. Number 6735 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 756072-28. Photo by Al Christianson.

Burlington Northern 6724 leading a coal train on March 22, 1981. Number 6724 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 756072-17. Photo by Al Christianson.

Burlington Northern 6710 leading a train through Newport, Minnesota on February 9, 1982. Number 6710 is an SD40-2 built by Electro-Motive Division (EMD), builder's number 756072-3. Photo by Al Christianson.