Gold mining in Alaska, a state of the United States, has been a major industry and impetus for exploration and settlement since a few years after the United States acquired the territory from Russia. Russian explorers discovered placer gold in the Kenai River in 1848, but no gold was produced. Gold mining started in 1870 from placers southeast of Juneau, Alaska. Gold is found and has been mined throughout Alaska; except in the vast swamps of the Yukon Flats, and along the North Slope between the Brooks Range and the Beaufort Sea. Areas near Fairbanks, Juneau, and Nome are responsible for most of Alaska's historical and current gold production. Nearly all of the large and many of the small placer gold mines currently operating in the US are in Alaska. Six modern large-scale hard rock mines operate in Alaska in 2008; four of those are gold-producing mines. There are also some small-scale hard rock gold-mining operations. Alaska currently produces more gold than any state except Nevada.