Welcome to Tualatin River National Wildlife Refuge!
The entrance to the Refuge can only be accessed from the southbound lane of Hwy 99. If you're coming from the south, there's a place to make a legal u-turn just past the Refuge entrance. Make your way up the entrance road, past the small building (looks like a fee booth, but don't worry, there's no fee to enter), then find a spot in the parking lot.