Chilkoot Pass, Alaska - 1898
Hundreds of miners hoping to strike it rich in the Yukon Gold Rush make the tedious climb out of the US and into British Columbia.
Canadian authorities would deny you entry if you did not bring at least a year's worth of food and other supplies to ensure your nominal survival in the backwoods.
Each man had to make countless trips up and down the slope, carrying 40 to 50 pounds each time, until they had moved all their required gear, (roughly 1,000 pounds total) to the top.
A step out of line to take a breather meant you might have to wait an hour or more before someone feeling generous would stop their climb to let you back in.
By the time of this picture, a cable tramway had been installed to help ease the slog, and eventually, the White Pass & Yukon Railroad would be constructed nearby and mercifully make this back-breaking section of trail obsolete.