Approximately 300 huge logs were cut and transported along the Willamette River to a chute that lifted the logs to the build site. To keep from damaging the fifty two exterior logs, steel bars were inserted in the ends for handling. The bark remained intact to create a rustic look. In true pioneer fashion, only ax and adze were used to fit the logs. Hardly a nail or bolt was used in the original construction. During the exposition, it served as a testament to Portland as the top lumber manufacturing city in the U.S.

The Forestry Building displayed exhibits, both during and after the fair, about wood products, forestry, and the perils and prevention of fire. During the fair, life-like specimens of animals native to the region lurked throughout the main gallery. Several hundred prints and photographs depicting the native tribes of North America adorned the gallery walls. A pipe organ in the upper gallery provided daily concerts for the visitors.

After the exposition, an unnamed New York promoter offered $200,000 to purchase the building. He planned to dismantle it, ship it around Cape Horn, and reassemble it at Coney Island. His offer was flatly refused and the building, along with its exhibits, was donated to the city of Portland. The Portland parks department nursed the building through years of harsh weather, economic depressions, and extensive use.

A citizen's committee, headed for many years by veteran forest researcher Thornton T. Munger, kept a faithful vigil over the building and the exhibits inside. Over time the building and the exhibits deteriorated. In 1914, with the help of a $6,000 donation from railroad titan James J. Hill, a reinforced concrete foundation was laid under the building. In 1952, the citizen's committee, known as the Gallery of Trees Committee, decided it was time to breathe new life into the old building. With support from the timber and wood products industries, $100,000 worth of new and used forestry tools, equipment, and exhibits were installed. The building and grounds where improved and a shay logging locomotive and some steam donkey engines were exhibited outside.