Marymoor Park is not listed as one of the C.O.L .A. parks in Seattle but it is one worth mentioning! The largest off leash dog area in the state, Marymoore offers 40 acres of maintained off-leash walking trails. We were there on an overcast Saturday afternoon and there must have been 200 dogs! This is THE spot for spot if he's in a social mood!
Expect to pay $1.00 for parking. Marymoore park is open 8 am - dusk daily.