Glacier National Park
Set on 1 million acres of the Rockies in northwestern Montana, Glacier is about as untamed a wilderness as you're likely to find in the lower 48 states. Yes, it can be cold, but isn't that fun in the heat of August? Short cruises ferry visitors to the edges of the mountains, where impromptu snowball fights often break out. Because the park is so isolated, it's easy to find a trail or mountain meadow where your family can commune with nature uninterrupted.
Setting Up Camp
The two lodges at Lake McDonald and Many Glacier offer restaurants, groceries, gasoline, ranger-led hikes, boat cruises, fishing, and horseback riding. (Rates start at $135 per night; 602-207-6000.) If your kids have stamina, the long (7.5 miles) but easy hike to Granite Park Chalet is worth the effort, if only to see the bighorn sheep, mountain goats, and grizzly bears ($60 per person per night; 406-387-5555). Only 2 of 13 campgrounds, Fish Creek and St. Mary, allow reservations ($17 per night; 800-365-2267).
Stop by Apgar Visitor Center, which plans special family activities throughout the summer. Families also love the narrated lake cruises from Many Glacier, St. Mary's, and Two Medicine, offered by Glacier Park Boat Company, in which guides point out moose and grizzly bears dozing in the piney shadows, then drop you off to hike on trails intersecting with lakes and glaciers (prices subject to change: adults, $11; kids ages 4 to 12, $5; 406-257-2426).
Rocks at the edges of the lakes and streams are tempting to play on but slippery. Have your kids wear water shoes to help prevent falls.