The Friends of Mount Pisgah Arboretum was founded in 1973 when it began building trails, building bridges, removing invasive species and publishing newsletters. Wildflower and mushroom shows first took place in 1981; hiring began in the early 1980s. The Arboretum's original mission was to have international plantings, but most of the early international donations were moved from the site. This has changed to preserve the Pacific Northwest's plant communities, provide environmental education programs, and enable public enjoyment of their site. The arboretum includes 7 miles (11 km) of river trails with 23 bridges, riparian meadows, evergreen forests, a rare section of preserved oak savannah, hillside Douglas fir and incense cedar forests, a water garden, wildflower meadows, a wooded picnic area and restrooms. The White Oak Pavilion replaced the deteriorating Quonset hut in 2005.