Well Al, since you included Canada... I love going to Algonquin Park. While it IS a national park, I never found it to be crowded when we did visit there. There are lots of trails to walk that can be done within a day. In fact, you can hit several of the trails in one day. Lots of waterfalls, granite and beauty everywhere in that park! I really loved going during the fall as well.. you wouldn't believe the colors!
Make sure you get up early enough to see the moose!
http://www.algonquinpark.on.ca/