I went last summer, in August. You can rent bikes or hike, theres a good amount of trail to fill up your afternoon. Depending on the weather, you can check out rappelling (if its been warm) or a glacier hike (if its been cool). They have zip-lining, which is expensive and short-lived. Still fun though.
Also, check out the local pubs. Some of them were decent, as I recall.
Definitely stop in Vancouver on your way back, too. I love that city.