We’d walked for hours, breaking the portage into stages, shuttling loads back and forth. Four trips per stage. Nine stages total. Black flies sounded like rain landing on my hood. My daughter was ahead with a dry bag, picking her way through dog-hair spruce. The canoe bit into my shoulders. Wind turned our 17-foot boat into a weathervane, forcing me to stop every few minutes. Twelve days into our trip, we were carrying our boat and gear 36 mile…