The Wenatchee Mountains are a range of mountains in central Washington State, United States of America. A major subrange of the Cascade Range, extending east 50 miles (80 km) from the Cascade crest, the Wenatchee Mountains separate the drainage basins of the Yakima River from the Wenatchee River. The crest of the range forms part of the boundary between Chelan and Kittitas Counties.

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 called the river Tâpe têtt, 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.