A great stop to get out and stretch your legs. The lodge is beautiful in itself, I love the sun porch as a great place to drink a cup of coffee and enjoy the amazing view of the lake, especially at sunset. But for the kids there is a great beach (shallow for a while so you could dip your toes in the incredibly cold water!) You can rent a canoe or a boat by the hour. Play on the beach or hike Marymere Falls.
The Marymere Falls hike is one of my favorite hikes. It's short, beautiful and worth the time. You can get there from the lodge or the parking lot by the lake (after exiting from the hwy take a left for the lodge or a right to the parking lot and trailhead) It's also really worth it to check out the Olympic Park Institute (www.naturebridge.org/olympic-park) ahead of time to see if they have any amazing activities to take part in.