A diverse group of peoples, Athabascan Indian, Eskimos and Aleuts, lived a subsistence life along the shores of the Yukon and Tanana rivers for thousands of years. Referred to as Alaska Natives, they had different cultures, languages and beliefs. When the United States purchased Alaska from Russia in 1867, little was known about its Interior. In 1885 Lt. Henry Allen made the first 1,500-mile expedition, mapping the Copper, Tanana, Yukon and Koyukuk rivers. The town of Fairbanks came into existence in 1902 when Felix Pedro, an Italian immigrant, discovered gold on the Chena River., the Klondike Gold Rush of 1897-98 was on in the Yukon Territory. With other key gold strikes made north of town, a trading post was established. As a bustling mining town, Fairbanks became incorporated in 1903, named in honor of Charles W. Fairbanks, a senator from Indiana. Within five years, it became the biggest city in Alaska. Most of the gold found in early Fairbanks was near bedrock, sometimes 100 feet or more down; mining was a dangerous occupation. Steamboats on the Chena River also played an important role in the area’s development. When gold production declined in 1911, so did the economy. In 1953 during the Cold War, construction of the 626-mile pipeline to transport fuel from the port in Haines to Fort Greely, Eielsen AFB and Ladd AFB (now Fort Wainwright), strategic military bases that guarded the Alaska Range. Today, Fairbanks has a diversified economy with oil, gas, gold and coal mining, military bases, a major tourism industry and the University of Alaska.