 American exploration of the area began in 1851, when prospector Samuel Hancock was led by Indian guides on a canoe up the Stillaguamish River.The area was opened to logging after the signing of the Treaty of Point Elliott in 1855 between the United States government and the Stillaguamish tribe, who were relocated to trust lands and the Tulalip Indian Reservation.The U.S. Army built a military road connecting Fort Steilacoom to Fort Bellingham, crossing the Stillaguamish River near the confluence.