UP 7878 lead a heavy freight west up Knapp Hill between Knapp and Wilson, WI on its mainline to the Twin Cities from Altoona, WI. Trouble with signals slowed the train, so it is making quite a grind up this ruling grade between Altoona and the Minnesota border at Hudson. This site is where the eastbound Twin Cities 400 flew off this curve on August 5, 1959, injuring a number of passengers. Cars ended up down on US 12 well below the curve.
