[7] Like almost all Native tribes, Indigenous groups on the Lewis River experienced a population collapse as a result of an 1830 epidemic introduced by early colonizers.

This is one of the reasons many early recorded observations include large shifts and changes in tribal populations.

[9] The Donation Land Claim Act of 1850 brought an influx of colonizers to the region, but just prior to that in 1845, Adolphus Lee Lewis retired from the Hudson's Bay Company and established a land claim near present day Woodland.

[9] The Lewis River rises in the Cascades in northeastern Skamania County, high on the west flank of Mount Adams, approximately 75 miles (121 km) northeast of Portland, Oregon.

It flows generally southwest through Gifford Pinchot National Forest, across central Skamania County, passing south of Mount St. Helens.

The East Fork flows westward from headwaters on the western flanks of Lookout Mountain in Skamania County.