LASSEN VOLCANIC NATIONAL PARK

The great outdoors is not so great when it's crammed full of other people. That's one reason why it's worth seeking out a lesser-known park; another is that these spots tend to be more affordable than the Yellowstones and Yosemites.

Lassen National Park is one of our favorites. Located in California, about five hours north of San Francisco, the park has steaming fumaroles, boiling pools, and plopping mud pots with the kind of snigger-inducing names (Bumpass Hell, Fart Gulch) that kids love. Other activities include horseback riding, fishing, boating, kayaking, and hiking to take in spectacular views of the Cascade and High Sierra mountains. Eight campgrounds dot the park, but for those of us who just can't give up clean sheets, hot showers, and bug-free nights, the Drakesbad Guest Ranch offers rustic accommodation in its 13 cabins and six lodge rooms; there's also a restaurant, horseback riding, and a hot spring–fed swimming pool. The rates—from $155 for adults, $85 for kids 2 to 11—include three daily meals; for extra savings, the ranch has shoulder season specials (June 4–19, August 24–September 3, September 7–October 12). There are plenty of other lodges, cabins, and B&Bs for all budgets in the vicinity. So it's time to pry that Nintendo DS out of your child's grubby little hands and force him to commune with nature.

NEXT: Whatever floats your boat