Dean M. Chriss
Koosah Falls, Oregon

Koosah Falls, Oregon

(Click image to enlarge)

Koosah Falls is the second of three major waterfalls on Oregon's McKenzie River. It drops about 70 feet (21 m) into a deep pool and is surrounded by lush forest. Less than a mile upstream is the first major waterfall on the McKenzie River, Sahalie Falls. 

Although the Mackenzie River originates just a few miles upstream at Clear Lake, it sustains a high water volume all year long. This is due to the large drainage area to the northeast, which consists largely of lava flows. Water here seeps quickly underground to form one of the largest aquifers in Oregon. The aquifer emerges in the form of springs around Clear Lake, helping to make the Mackenzie River one of the most consistent perpetual rivers in the northwest.