Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Waldo Lake Wilderness is a wilderness area surrounding Waldo Lake in the central Oregon Cascades. It is located within the Willamette National Forest. It was established in 1984 and consists of 37,162 acres (15,039 ha).Ninety-eight percent of the Waldo Lake Wilderness is covered by forest on moderate to steep terrain, which ranges in elevation from 2,800 to 7,144 feet (850 to 2,177 m).Waldo Lake itself is outside the wilderness boundary, but it is considered one of the purest lakes in the world: vertical visibility can exceed 100 feet (30 m). It was scooped out by ancient glaciers, and is Oregon''s second largest lake at 10 square miles (26 km2) with a maximum depth of 420 feet (130 m).