The last 150 years of Anasazi-Pueblo occupation of Mesa Verde was filled with turbulence. Long distance trade declined, conflicts escalated, a large drought occurred, and large population shifts occurred. Some areas simply could not produce enough food to support the population. For over 600 years people had lived next to the areas that they farmed. Drought occurred between 1130 and 1180. At this time people began walking to their farms, as they were now living closer to their water source. Before long, prosperity returned and much of the population was living in larger settlements. This period saw a boom in both construction and population growth. Population at this time probably peaked at between 15,000 to 30,000. In addition, there were at least another 30,000 people living in the surrounding areas. However, another severe drought would occur betweenn 1276 and 1299, and severe food shortages would soon occur. This drought would end at least 600 years of Anasazi-Pueblo occupation of the Four Corners-Mesa Verde area. At this time tens of thousands of people would migrate out of this area permenently to other parts of the Southwest.