Centuries-old traces of the early Indians can be found throughout the American Southwest in New Mexico, Arizona and southern Utah and Colorado. Cliff dwellings and other structures have been preserved in more than a dozen national parklands and monuments.

Most of them have park facilities nearby, and most can be reached by car, except where noted.

Among the most dramatic of the Indian ruins:

Chaco Culture National Historical Park, New Mexico: The impressive Pueblo Bonito, built between the 11th and 12th centuries, is believed to have contained 800 rooms housing 1,200 Chaco people. Canyon de Chelly National Monument, Arizona: The pueblo ruins, important as they are, take second billing to the beauty of the red-rock canyon in the heart of the Navajo Indian Reservation. Indian guides will seat you in the back of an open truck and take you up the canyon to the excellent White House ruins. Part of the way is through the shallow river that runs through the canyon.

Montezuma Castle National Monument, Arizona: The five-story, 20-room castle is set high in a limestone cave. It is one of the better preserved of these prehistoric apartment buildings.

Casa Grande National Monument, Arizona: Unlike most of the other ruins, this is not a cave dwelling but a four-story, 11-room earthen structure that rises up from the desert. It was built in about 1350 and may have been used for a lookout or for ceremonies.

Gila Cliff Dwellings National Monument, New Mexico: Well-preserved, the cliff dwellings sit at the mouth of caves carved into a high bluff overlooking the valley floor.

Navajo National Monument, Arizona: The easy way to view Betatakin, a large cliff apartment set inside a cave, is from afar. But the hardy can take a strenuous guided hike (three hours round trip) for a close-up look.

Tonto National Monument, Arizona: You have to hike here, also, to see two separate ruins in high caves. The lower one has 19 rooms (an hour's walk) and the upper has 40 (three hours).

Tuzigoot National Monument, Arizona: This is a very large ruin on a high hilltop pueblo, a 110-room structure begun in about 1125 and added onto for two centuries.

Walnut Canyon National Monument, Arizona: Dating from about the year 1000, these ruins represent a more primitive form of cliff dwelling. The Indians took advantage of long shelves in the limestone cliffs, which served as floor and ceiling for their homes. They walled up the open side, forming a long dwelling of linked rooms.