The Delbert Hunter Arboretum and Botanical Garden in Dallas, Oregon is a three and a half acre garden planted only with native Oregon plants. In the garden are several color forms of R. macrophyllum and R. occidentale. Dr. Frank Mossman, who has explored the occidentale regions in Oregon and California, provided some of the occidentale plants. A number of the plants were also grown from wild-collected seed from the American Rhododendron Society Seed Exchange.

Located at the Dallas City Park, The Friends of the Arboretum meet weekly on Tuesdays to care for the garden and the Interpretive Center, learn about native plants and enjoy coffee.