Yakima River (Wash.)

The Yakima River is a tributary of the Columbia River in south central and eastern Washington state, named for the indigenous Yakama people. Lewis and Clark mention in their journals that the Chin-nâm pam (or the Lower Snake River Chamnapam Nation) called the river Tâpe têtt (also rendered Tapteete), possibly from the French tape-tête, meaning "head hit". The length of the river from headwaters to mouth is 214 miles (344 km), with an average drop of 9.85 feet per mile (1.866 m/km). It is the longest river entirely in Washington state.