The pratt-truss logwork supports the roof purlins and rafters above. The trusswork is reinforced with tie rods, undoubtedly necessary because of the heavy snow loads. New spotlights have been attached to the historic fabric on the interior to highlight the interpretive exhibits. Some appear to be placed where original lights were. Suspended acoustical panels were also added to cut down on interior noise.
Interior walls are the exposed logs.
On a sunny day the most used portion of the room is the south end which is outfitted with a telescope through which a viewer can see parties climbing the northwest slopes of Mount Rainier. At the north end of the main room is an enormous coursed rubble fireplace, added in 1952. The fireplace opening is approximately 4.5x6 feet and holds simple andirons. Behind the fireplace at the north end of the building are two levels of office and storage space, the partitions of which appear to have been moved several times. The new floor of the main room is wood boards laid diagonally.