The Hoyt Arboretum is located atop a ridge in the west hills of Portland, Oregon, United States. When the 160 acre (64.75 hectare) Multnomah County Poor Farm Hillside Farm west of Washington Park closed in 1922, the land was donated to the City of Portland to be used as a park, which later became Hoyt Arboretum. The property has since increased in size through additional donations and acquisitoons to 189-acre.