Anonymous wrote:and at what age?
Itching to take my boys (4 and 2) out west to see some great national parks.
Well, given that Rock Creek Park and the National Mall are national parks, it would have been when they were very tiny. I'm not sure exactly when.
If you're talking about a longer vacation, we did Banff (not a US national park, but a very similar experience) when DS was 5. He was old enough to be easy to travel with, and to enjoy things like very low key "white water" rafting (no real white water on the trips that take 5 year olds), horseback riding, short hikes, museums etc . . . Before that we'd done other outdoorsy things in the context of vacations that also included other things, or day trips to Shenandoah.