Tour follows the Tieton River down to its juncture with the Naches River

Two Native American names apply to the Tieton River. East of the Cascades, the common name in use was Shanwappum, meaning milky water, and was appropriate for this glacial river.

The present name is a corruption of Taitinapam, which relates to a tribe in Cowlitz River Valley on the west slope of Cascades, who spoke the Yakama language and were affiliated with Naches Tribe. The river itself appears to have been named Tai-Tin by this tribe. Other places with the name Tieton are related to the Tieton River. The Yakima Tieton Main Canal flume parallels the road along the south bank of the river