The search for what mineral led to a rush of prospectors to Alaska?

Alaska's gold rush began in 1896-97 when gold was discovered in the Klondike in Canada's Yukon Territory. Lured by the hopes of quick riches, thousands of prospectors streamed through the Pacific Northwest and Alaska, demanding goods and services. With the best gold fields claimed by 1898, many began searching in Alaska. Major strikes occurred in Nome in 1898 and near Fairbanks in 1902. Most of these stampeders did not get rich, but a good number decided to stay in Alaska afterward, quickly transforming its population.

Source: Library of Congress