Fifteen thousand years ago, cataclysmic Missoula floods reshaped the lower Tualatin and Willamette area, creating the basin of Oswego Lake and sending the Tualatin River into a new channel above Willamette Falls. The confluence of Oswego Creek and the Willamette River had been a site of human activity for thousands of years, and archaeological evidence shows Native Americans lived there 6,100 years ago, with projectile points and other artifacts linked to an ancient people from the west side of the Cascades who obtained obsidian from south central Oregon. When Euro-Americans arrived in Oregon, the lower Willamette River was occupied by the Clackamas branch of the Chinookan people, while land west of Oswego Lake was occupied by the Tualatin band of the Kalapuya Indians, a semi-nomadic people who relied on hunting and gathering. The Chinooks were bay and river people who depended on fishing and trading at places such as Willamette Falls, and the nearest Clackamas village stood just south of the falls. At the mouth of Sucker Creek, now Oswego Creek, the Clackamas caught salmon, suckers, and eels with fixed baskets. Their custom of head flattening marked status by distinguishing free Chinooks from slaves, and their trading influence was so great that Chinook Jargon, combining Chinook, French, and English words, became the trade language of the Northwest. Early settlers said the lake was called Waluga after the wild swans that wintered there, though linguists have not traced the word in native dialects, while the name of Sucker Creek may derive from the Kalapuyan term “tch'aká mámpit ueihépet,” meaning “sucker-place creek.” Contact with Euro-Americans brought catastrophe through smallpox, measles, and malaria in epidemics between 1792 and 1847. After contact with sick sailors on the Owyee, the first ship to sail up the Willamette, nine-tenths of the Clackamas died in the winter of 1829-30. By the time white settlers arrived, few Native people remained in the Willamette Valley, and in 1856 the surviving 88 Clackamas were removed to the Grand Ronde Reservation, far from their homeland, where intermarriage with other tribes ended their existence as a separate people. The U.S. government never honored the treaties it negotiated with the Willamette Valley tribes.