Big Muddy River Here the outline of the Wisconsinan Era lake bed is evident in what were the northern reaches of the ancient lake, where the lake bed was only a few hundred feet wide. The steep Illinoian hills are suddenly truncated where they meet the flat bottom of the Wisconsinan Era lake bed. Here the tributaries of the Big Muddy are tiny, intermittent streams, meandering though these narrow valleys at the headwaters. The Big Muddy basin contains a significant portion of the planet's coal reserves. Most of this is hidden under its deep mud. At a few places the river has eroded
Muddy River (Washington) 83 and passes the Ape Canyon Trailhead and the Lava Canyon Interpretive Site, both on the left, before entering Muddy River Gorge. Flowing northeast through the gorge, the stream plunges over three waterfalls before emerging from the narrows and curving sharply again to the southeast. Here Crane Lake is on the left, Smith Creek enters from the left, and Smith Creek Trailhead is on the right. Slightly downstream of the trailhead, the river leaves the national volcanic monument but remains in the national forest. At about the level, Clearwater Creek enters from the left. Turning south, the river descends less