The Port Gamble trails are a fantastic network of intermediate trails.  While there's no huge payoff at the top, like Tiger Mountain, there are trails in very good condition that cover a lot of area.  You will spend some time on logging trails and you may get lost if you're not careful.  It's a good idea to bring your smartphone with a map and GPS, the Maprika application is a very handy tool for this expansive area.  You will get a very good workout after a couple of hours on these trails, and it will be a good idea to bring water and a snack.  There is cell coverage in about 90% of the area.