As progressive as the Pacific NW is in some ways, it's surprisingly backwards in others. It constantly amazes me that there are so few off leash areas, given the percentage of people in the Seattle area that own dogs.  Below is a list of organizations working to develop more off leash areas.  Please support them!
Off Leash Parks in S King County

Off Leash Parks in S King County

Grandview and Marymoor Off-Leash ParksThese two parks are managed by S.O.D.A. The Marymoor off-leash dog area was the first area created by this group and is located in a section of Marymoor Park in Redmond. Grandview (where China and Chelsea [see About Us page]) play, is a 37-acre off leash park. It is currently King County's only single use park devoted exclusively to off leash dogs.
Off Leash Areas in KentThis group has been trying for years to get Kent to recognize the need to have dedicated off leash areas in Kent, WA. To express The Camping Dog's frustration, we find it amazing that a city this size, with the 2nd largest percentage of dedicated park land in King County, has yet to recognize that more than half of its citizens own dogs and need parks. For those visitors familiar with this area, please bury the Kent City Council with emails demanding they address this need. K-Dogs can really use your support. Please email them to be added to the list - you won't get buried under pointless emails, but will be kept informed of Kent city actions.