"As soon as you start walking, stay straight at an unsigned junction, and you’ll get your first glimpse of the contrasts ahead when you’ve walked only 500 feet on this trail. At this point you’ll be at the top of a little bluff, looking out over a wide area of rocks. Those rocks used to be on the upper slopes of Mount St. Helens, but on May 18, 1980, they tumbled down the hill at about 45 miles per hour, part of a lahar, or mudflow, triggered when the Shoestring Glacier melted moments after the volcano erupted.
But the mudslide stayed generally within the boundaries of the Muddy River, so the forest you’re standing in—even though it was within feet of the slide— was spared. You’ll spend the next 5 miles climbing this ridge, but don’t worry: you’ll gain only around 1,500 net feet along the way."