The trail of farmers is easier to follow. They have a dependable food supply and live in one spot for generations. They build villages and cities, and best of all, excellent garbage piles. Nothing delights the archeologist as much as a big pile of trash for every piece is a paragraph in the story of a people. If he can find the things people have used, worn out and discarded the archeologist can reconstruct their lives to an amazing degree. Hunters seldom pile up their trash but farmers are more obliging. Living for generations in a village they carry it outside and dump it in one nice big pile. And in those successive layers of trash is the story of the people. The archeologist revels in it. Except for the professional garbage collector he is probably the only person in the world who is thankful for trash. Excavation of ruins and trash piles has revealed that the Mesa Verde region was occupied by farming Indians from about the beginning of the Christian Era, possibly somewhat earlier, until almost 1300 A.D. For convenience this long occupation has been divided into four archeological periods. Actually there were no abrupt breaks between these periods. Once the farming Indians settled in the area they developed steadily and there was constant progress until the climax was reached. Dividing the occupation into periods makes it much easier, however, to follow the progress of the people. Various archeologists have used different names for the periods but we shall use a system that was developed by Dr. Frank H. H. Roberts, of the Smithsonian Institution. Dates for the various periods vary somewhat in different parts of the Pueblo area but those used here serve well for the Mesa Verde itself. Basket Maker Period. 1 to 450 A.D. Modified Basket Maker Period. 450 to 750 A.D. Developmental Pueblo Period. 750 to 1100 A.D. Great Pueblo Period. 1100 to 1300 A.D. The fact that the first two periods are called “Basket Maker” and the last two “Pueblo” should not be considered as an indication that there was a difference in the people themselves. Many years ago it was felt that during the eighth century there was a change in the physical type but this idea has been discarded. The people as well as their culture seem to have progressed in an unbroken line. It should be noted, also, that the dates are not rigid and they do not indicate abrupt, easily discerned cultural changes. BASKET MAKER PERIOD. 1 to 450 A.D.