The 189-acre (76 ha) arboretum is located atop a ridge in the Tualatin Mountains two miles (3.2 km) west of downtown Portland.

[3][4] Hoyt Arboretum is sited on steep slopes, straddling the SW Fairview Boulevard ridge above the Oregon Zoo and the Portland Japanese Garden.

[6] After the Poor Farm closed, in 1922 Multnomah County sold the land to the City of Portland, which created Hoyt Arboretum in 1930.

[7] The city commissioned John W. Duncan, superintendent of parks for Spokane, Washington, to design a plan for the new arboretum.

Works Progress Administration crews cleared the forest and built the roads and paths winding through the arboretum in 1930 and 1931, although some native trees that had grown in the wake of the 1889 fire were left in place.

[9] The Stevens Pavilion is a covered A-frame picnic shelter with wooden beams and stone floors, nestled in a grove of Douglas-fir trees.