The American River is a tributary of Naches River, in Washington of United States. It flows down the east side of Cascade Range, through Wenatchee National Forest and the William O. Douglas Wilderness.

From its source from American Lake, it flows to north for several miles, picking up its tributary Rainier Fork American River, which flows east down from the neighbor Chinook Pass. State Route 410 crossing Chinook Pass from Mount Rainier National Park, then following Rainier Fork and the American River valleys.

The American River is part of the Columbia River basin, being a tributary of the Naches River, which is tributary to the Yakima River, which is tributary to the Columbia River.