Lake of the Woods is located near the crest the Cascade Range in southern Oregon, southeast of Mount McLoughlin. Most of the lake water comes from groundwater seepage; however, there are also three tributary creeks. Rainbow Creek is a year-round tributary, while Billie Creek and Dry Creek have only seasonal flows. The lake's only outlet flows into Great Meadow, a wetland at the northeast end of the lake. Great Meadow drains into Seldom Creek, which flows into Upper Klamath Lake. Lake of the Woods only discharges water in the spring. During the drier summer and fall months, lake water is lost only through groundwater seepage and evaporation.