I love Breazeale Interpretive Center for the courses they teach for FREE including birding, plant identification etc. There is a wonderful walk in the woods that is used as the teaching classroom and the actual center has displays dealing with our natural environment. Great place for adults and children.
In the Padilla Bay area, don't miss this center. Beautiful center with wonderful displays to explore. My favorite to check on are the octopus! Take a walk down to the bay, travel down the circular staircase and enjoy a walk along the water (if you hit the tides correctly).