As I recall, they were UP single-deck cars. No idea where they came from. The shipments went on for a few weeks. I just remember fervently hoping that I wouldn't have to go any nearer them that I had to, although I did once work a yard job that was spotting and pulling the stockyards down by Ortega (the west end of Stockton yard, on the other side of the main line). These are memories that tend to linger...