Mesa Verde National Park isn't as well known as Yellowstone or Yosemite, but annually, an average of 670,000 people make the trek to southwestern Colorado to explore the ancient cliff dwellings.

Just 290,000 souls visit Great Sand Dunes National Monument in south-central Colorado each year. "We're not a destination park yet," said the National Park Service's Kathy Brown. "Usually people stop on their way to or from Mesa Verde."

Both areas are national gems that offer unique experiences.

Because the cliff dwellings at Mesa Verde are archaeological treasures that could easily be damaged or destroyed by visitors, park rangers take a limited number of people on group tours through three of the dwellings -- Cliff Palace, Balcony House and Long House -- for $1.75 a head. That's a bargain. Visiting at least one of those three sites is a must, and you should plan on spending at least a day at the park, if not longer.

A warning: Visits to cliff dwellings can be strenuous. Officials recommend that people with heart or respiratory ailments not visit the dwellings because getting to them requires climbing a lot of steps and ladders. Parents must keep close watch on children, especially near canyon rims.

There are some self-guided sites, and visitors can see 35 to 40 dwellings at a distance from overlooks, which help put the entire park in perspective. There are 4,000 archaeological sites, including 600 cliff dwellings. The area is so rich in sites that when fire burned 4,700 acres in 1996, it revealed 400 new ones that had been obscured.

For that reason, back-country hiking is limited to several trails, and camping is only allowed in the campground.

Not so at Great Sand Dunes, most of which is considered wilderness. Hikers and campers can and do trudge into the dunes to spend a night or two. Of course, they must bring water. It's easy to kill a day at the park hiking the dunes. While temperatures can hit 85 in the summer, nights are cool and campers witness a sky brilliantly sprinkled with stars. Meanwhile, there is a movement to get National Park status for Great Sand Dunes.

Getting there

Mesa Verde is about 35 miles west of Durango or about 10 miles east of Cortez, which is near the Four Corners area. Any way you cut it, it's a long haul from Minnesota, unless you fly, of course. But if you're driving to Utah, Arizona or points west, it's on the way.

Where to stay

The huge campground at Mesa Verde never fills up and reservations aren't taken. There aren't many recreational-vehicle hookups, however, though there are some campgrounds just outside the park. The park's Far View Lodge, with 150 rooms, offers spectacular views and mule deer below your balcony. And no TV, phones or pools, in keeping with the wilderness atmosphere. There is a restaurant. Otherwise, major motels are available in Durango and Cortez. Durango, quaint, trendy and crowded with tourists, is worth a visit. There are blocks of shops, restaurants and taverns, all of which stand in stark contrast to the Mesa Verde wilderness.

At Great Sand Dunes, the 80-site campground can fill on weekends and holidays, but if you get there early, you generally can get a spot. Private campgrounds and a lodge are just outside the park. Come prepared: The closest town is Alamosa, population 5,000, about 40 miles away.

For more information

For Mesa Verde, call 1-970-529-4465 or write P.O. Box 8, Mesa Verde National Park, CO 81330. For Great Sand Dunes, call 1-719-378-2312 or write Great Sand Dunes National Monument, 11999 Hwy. 150, Mosca, CO 81146. Or check out the National Park Service's Web site at http://www.nps.gov/meve or http://www.nps.gov/grsa. (You can also access any of the other national parks or monuments from the Park Service Web site.)