The Oregon Garden in Silverton, Oregon, opened in 1999 as a 130-acre public botanical garden with more than 20 specialty gardens, event spaces, and year-round access. Long proposed by the Oregon Association of Nurseries and realized after Silverton sought a productive use for reclaimed wastewater, it combines horticulture with water treatment through terraced wetlands and 25 ponds that cleanse water for reuse in the garden and nearby farmland. Its grounds include notable plant collections, a historic Oregon white oak grove with the 400-year-old Signature Oak, and the Gordon House, the only Frank Lloyd Wright-designed house in Oregon open to the public in the Pacific Northwest.