Unit trains going south usually do run about 100 cars with two buffer cars. Coming back north, the UP has a length limit for the FRC, so the unit trains are split into two near equal parts. This helps on the OT also due to relatively short passing sidings. They must have a buffer car between the power and the tanks, but seem to run with or without a buffer car at the end. They have been know to grab just about anything as a fill in buffer for the northward moves, even auto racks! The SD-60Ms are likely local power, probably in Klamath Falls. No doubt they were going in for periodic inspections.

Robert