On the second day of their December 2020 voyage through the punishing Sierra mountain range, the four team members of the Forlorn Hope Expedition woke to find six inches of snow had piled on their tents, and more was falling. They made oatmeal on their camp stoves and hustled to get moving. The previous day, they had covered ground that a group of pioneers in the winter of 1846-47 had needed a week to accomplish—and they would ultimately traverse 100 miles in five days, versus the pioneers’ 33. Both parties…