 By 2,000 to 3,000 years ago, settlements in the Clackamas River basin, adjacent to the Johnson Creek watershed, had moved to the river's lower floodplain.The area was the home of the Clackamas Indians, a subgroup of the Chinookan speakers who lived in the Columbia River Valley from Celilo Falls to the Pacific Ocean.The Clackamas lands included the lower Willamette River from Willamette Falls at what became Oregon City to its confluence with the Columbia River and reached into the foothills of the Cascades.