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 (853 to 2,177 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).

Vegetation in the Waldo Lake Wilderness consists mostly of Douglas-fir, mountain hemlock, and Pacific silver fir.

Primary activities in the Waldo Lake Wilderness are hiking, camping, fishing, and boating.

Gasoline-powered motor boats on the lake have been banned since 2012 after nearly twelve years of public comment, deliberations, and decision making.