 River otter , beaver , nutria , mink , weasel , red fox , deer , elk , coyotes , raccoons , and rabbits make up a portion of the terrestrial animals . Other wildlife includes painted turtles , frogs , salamanders , crawfish , fish , and alligator lizards . The refuge is one of only ten national wildlife refuges in the United States located in an urban area . Groups have suggested that the refuge be expanded all the way to the Willamette River to provide a greenway through a heavily populated area . The Tualatin 's floodplain is the largest of any of the Willamette River ’ s tributaries . 
