The Alaskan Gold Rush brought renewed interest in the use of sled dogs as transportation. Most gold camps were accessible only by dogsled in the winter. "Everything that moved during the frozen season moved by dog team; prospectors, trappers, doctors, mail, commerce, trade, freighting of supplies … if it needed to move in winter, it was moved by sled dogs." This, along with the dogs' use in the exploration of the poles, led to the late 1800s and early 1900s being nicknamed the "Era of the Sled Dog".