harder lavas they cut out blocks of the tufa and with them built pueblos two or three stories high. The blocks are usually about twenty inches in length, eight inches in width, and six inches in thickness, though they vary somewhat in size. On the volcanic cones which dominate the country these people built shrines and worshiped their gods with offerings of meal and water and with prayer symbols made of the plumage of the birds of the air. When the Navajo invasion came, by which kindred tribes were displaced from the district farther west, these Tewan Indians left their pueblos on the plateau and their dwellings by the rivers below in the depths of the canyon and constructed cavate homes for themselves; that is, they excavated chambers in the cliffs where these cliffs were composed of soft, friable tufa. On the face of the cliff, hundreds of feet high and thousands of feet or even miles in length, they dug out chambers with stone tools, these chambers being little rooms eight or ten feet in diameter. Sometimes two or more such chambers connected. Then they constructed stairways in the soft rock, by which their cavate houses were reached; and in these rock shelters they lived during times powell-canyons-30.jpg A TYPICAL CLIFF DWELLING. 57 powell-canyons-31.jpg A ROOM IN A PUEBLO. 58 CANYONS OF THE COLORADO. of war. When the Navajo invasion was long past, civilized men as Spanish adventurers entered this country from Mexico, and again the Tewan peoples left their homes on the mesas and by the canyons to find safety in the cavate dwellings of the cliffs; and now the archaeologist in the study of this country discovers these two periods of construction and occupation of the cavate dwellings of the Tewan Indians. North of the Rio San Juan another vast plateau region is found, stretching to the Grand River. The mountains of this region are the La Plata Mountains, Bear River Mountains, and San Miguel Mountains on the east, and the Sierra El Late, the Sierra Abajo, and the Sierra La Sal on the west, the latter standing near the brink of Cataract Canyon, through which the Colorado flows immediately below the junction of the Grand and Green. Throughout the region mountains, volcanic cones, volcanic necks, and coulees are found, while the mountains themselves rise to great altitudes and are forest-clad. Some of the plateaus attain huge proportions, and between the plateaus labyrinthian mesas are found. Buttes, as stupendous cameos, are scattered everywhere, and the whole region is carved with canyons. Grand River heads on the back of Long's Peak, in the Front Range of the Rocky Mountains of central Colorado. At the foot of the mountain lies Grand Lake, a sheet of emerald water that duplicates the forest standing on its brink. Out of the lake flows Grand River, gathering on powell-canyons-32.jpg A NAVAJO READY FOR A JOURNEY. MESAS AND BUTTES. 59