After Simpson’s visit, other military expeditions and a few civilian parties probably entered the canyons. No archeological investigations were made, however, until 1882, when James Stevenson surveyed the area for the Smithsonian Institution, making sketches, photographs, and ground plans of 46 ruins in the two main canyons. Stevenson found two mummies in a rock shelter ruin in the northern canyon. Because of this find the ruin is known as Mummy Cave, and Stevenson gave the canyon a Spanish name, Canyon de los Muertos, or canyon of the dead men. The name has since been shortened to del Muerto. [Illustration: First Ruin in the lower part of Canyon de Chelly. It has 10 rooms and two kivas.] Later in 1882, Cosmos Mindeleff, also from the Smithsonian and a member of Stevenson’s party, mapped the canyons and showed the locations of some of the larger ruins. Mindeleff’s monumental architectural survey of the ruins of Canyon de Chelly was published in 1896, after two more visits. Much of our knowledge about material objects used by the early Puebloan inhabitants of the canyons comes from the work of the late Earl H. Morris, who excavated a number of the important cave sites in the 1920’s. Since then a comprehensive survey of the monument has been carried out by David L. De Harport for the Peabody Museum of Harvard University, and additional excavations have been conducted by National Park Service archeologists. [Illustration: The upper and lower White House ruins were probably connected when the ancient Indians lived there.] The Principal Ruins Within the national monument are perhaps 800 prehistoric and historic Indian village sites, representing various stages of Pueblo and later Navajo cultural development and spanning a period of about 1,800 years. The most interesting and important ruins are described below. WHITE HOUSE Located up the main canyon, about 6 miles from Park Service headquarters, White House is one of the largest, best preserved, and most accessible ruins in the monument. [Illustration: A kiva at the White House ruin, where religious and other ceremonies were held.] Lt. J. H. Simpson described this ruin after his 1849 visit, calling it Casa Blanca (White House). It is also known by its Navajo name, Kini-na-e-kai. Both names derive from a conspicuous white-plastered wall in the upper portion. White House was constructed in two sections; one stands against the base of the cliff on the canyon floor, and the other is in a small cave immediately above. Mindeleff estimated that at one time the whole ruin contained as many as 80 rooms. Much of the lower building has probably been washed away by the stream nearby (a retaining wall now helps to prevent this), but evidence of about 60 rooms and 4 kivas (special ceremonial chambers) still survives.