the first pottery in the northern Southwest was also made and used by groups who cultivated corn and possible other domesticates but relied heavily on hunting and gathering and still maintained and high level of residential mobility. Skibo and Blinman focus on early brown ware that is dominated by the seed jar shapes. An analysis of use-alteration traces reveals that many of the vessels were use for cooking but other were not. On the colorado plateau con appears much earlier than pottery , so they also explore way these people begin regularly make pottery by about A.D.200 Skibo and Blinman suggest that it may be to cook item, like beans that require long-term boiling which is a process that is not easily accomplished with stone boiling in baskets or skins