These attractions are becoming extinct, so experience them while you can.
Bear in Mind
Yellowstone Park, WY
The geysers thrill, but it's the wild woolly and feathered creatures (many of them threatened)—the grizzly, gray wolf, bald eagle, lynx, and wolverine—that are the stars.
how to see it
Stop at the Junior Ranger station and ask the ranger where the best sightings will be that day. Early morning and evening are when you'll have the most luck (during the summer, the gates are open 24/7). Or sign up for the ranger-led bus tour. More options: an escorted llama riding trip (yellowstonesafari.com) and the stagecoach wildlife tour (travelyellowstone.com), which includes an Old West steak-and-wiener cookout. Tweens can opt to meet you at the cookout via horseback.
where to crash
The Holiday Inn in West Yellowstone (holidayinn.com) is a rustic lodge. They set up dogsledding tours for guests, even in summer. The Grizzly and Wolf Discovery Center (grizzlydiscoveryctr.com) is five minutes from the hotel. Stop in to meet grizzlies Kobuk and Nakina, and check out two wolf habitats.
while you're there
Visit Grand Teton Park (nps.gov/grte). They offer junior ranger programs for kids and guided fishing outings for families on the Snake River. The parks are 90 minutes apart, so you may want to spend a night at the Homewood Suites by Hilton, in Jackson, WY. The suites are huge, and hot breakfast is free. Then take a dip at Boiling River Park. Stand with one leg in the chilly Gardner River and the other in the toasty Boiling River. Small “hot tubs” are carved in the rocks, and there are inlets where 'rents can watch wee bathers.