 The Tualatin River National Wildlife Refuge is a 1 @,@ 856 acres ( 751 ha ) wetlands and lowlands sanctuary in the northwestern part of the U.S. state of Oregon . Established in 1992 and opened to the public in 2006 , it is managed by the United States Fish and Wildlife Service . Located in southeastern Washington County , 15 miles ( 24 km ) southwest of Portland , the refuge is bordered by Sherwood , Tualatin and Tigard . A newer area , extending into northern Yamhill County , is located further west near the city of Gaston surrounding the former Wapato Lake . 
