In northern Arizona have been found many remains of prehistoric people who were contemporaneous with and had certain traits in common with the Anasazi, and it was originally thought that they all belonged to this culture. Later, and more intensive, studies have shown that the problem is more complex than was first believed. Apparently various tribes were represented, and at present archaeologists are not in agreement as to the cultures to which all of these groups should be assigned.[29] The people of the Kayenta region were Anasazis, but in north-central and northwestern parts of the state lived other people whose affiliations are not yet known with certainty. It has been suggested that the best known group may represent a branch of the Mogollon but it has not been definitely assigned to this culture. This group is called the _Sinagua_. It first occupied the area about the San Francisco Mountains and, later, the Verde Valley. The characteristic pottery is a brown utility ware of paddle-and-anvil manufacture, fired in an oxidizing atmosphere. The surface is smoothed and sometimes polished. Tree-ring dates have not been satisfactorily established for the earliest period, but, on the basis of pottery finds, it has been estimated that the San Francisco Mountain area was occupied between 500 and 700 A.D. by people who lived in round and rectangular pit houses with center firepits and long sloping entrances to the east. Roofs were of sloping poles covered with earth. These were followed by fairly deep, timber pit houses. Walls were made of a series of upright poles lashed together, with larger poles set in corners to provide support for a roof platform. The entire structure was covered with grass or bark, and earth was banked over it. These timber pit houses at first had long sloping entrances to the east, but these were later reduced to serve as ventilators, and entrance was through the roof. In locations unsuitable for the construction of pit houses, there were also surface or near-surface houses. In places where drainage was poor and the ground was boggy, they were built on artificially constructed earth mounds some eight to twelve inches high. These have been called platform or alcove houses. They are roughly rectangular and have a small extension or alcove which was used as an entrance. The alcove may have served a further purpose and supplied additional storage space, although rectangular surface granaries made of timber seem to be associated with these houses. [Illustration: Fig. 57—Map of the Southwest showing probable areas occupied by the Sinagua group and the Patayan Culture. Dotted area, Sinagua; 1. Southern branch, 2. Northern branch. Hatched area, Patayan; 3. Cohonina branch, 4. Prescott branch. (Based on maps by Colton[18][19] and McGregor.[87])]