Suggested by Amber! There is a park in happy valley that is perfect for the whole family. The kids playground is awesome next to a fenced in dog park with a area for small dogs and an area for larger dogs.
From Portland Pooch: Happy Valley Park has a modest-sized off-leash area located in the far end of the park (south of the parking area). The off-leash area is approximately a 1/2 acre in size, is fenced, and has poop bags and garbage cans near the entrance. The park is large enough for a decent game of fetch. There are many small trees, and a few larger trees near the edges of the park providing shaded areas. There is no water provided in the off-leash area, but there are facilities adjacent to the park where you can fill up your water jugs or bowls. The rest of the park has a stringent leash law, so keep your dogs on leash to and from the off-leash area.