Revised Question - Fun Things to Do from Vancouver to Grand Mound, Wa

Well, if you feel like heading North a few (15-20) more miles I have a few fun suggestions:

- Monarch Sculpture Park (exit 99), is a really fun and free (?) place to go. It's an artist retreat that then "shows" a WIDE variety of artists work throughout their 10 or so acres. My children really enjoy the noise garden, where they get to hammer, dong, ding, and ring the sculptures.
http://www.monarchartcenter.org/

- Wolf Haven, is outside of Tenino, WA. It's just what it's name says...a haven for wolfs! http://www.wolfhaven.org/index.php

- Olympia Farmer's Market.

- Olympia Hands On Children's Museum (a lot of fun and decently priced)
http://www.hocm.org/

I don't have any other ideas, but just a heads up, Stanley Park, China Town, Gastown, and Grouse Mountain are all in Vancouver, British Columbia, not Vancouver, WA, which I am assuming is your starting point since you are in Camas. They are all great suggestions if you want to continue your trip a little further north, though. :)

In Vancouver there is Stanley Park on the waterfront, China Town a really special one, Gastown and a trip on a hydrofoil to the other side the the harbor.
There is Grouse Mountain outside of town where you can go skiing and hiking.

If you are going to Mt. St. Helens take a side trip on Hwy 84 to Multnomah Falls. It's the longest waterfall in N America.