Best practices before a long tow through mountains

Before a long mountain tow, the checks that actually matter most: brake controller gain properly set for the grade and weight, tire pressure checked cold (mountain elevation changes affect this more than people expect), and bearings/hubs checked for heat at your first rest stop, not just before leaving. Mountain grades put more sustained stress on brakes and cooling than flat highway driving, so problems that were marginal on flat ground tend to show up here.