http://www.wsdot.wa.gov/ferries/your_wsf/our_fleet/index.cfm?vessel_id=14

From the Yakima word wenatchi for "river flowing from canyon."
When Lewis and Clark traveled through the Columbia River valley in
1803-1805, they mentioned the word Wenatchee in their journal,
hearing of the river and the tribe living along its banks.
A city, lake, river, and national forest are also named after the tribe.