Kept on hand for trade. Archaeologists have tallied up almost 70,000 bushels of underground Storage Capacity in the cascades of a single mandan village. The town of half. I grew up in new jersey. So bushels, and not really on my radar. As a benchmark, a bushel is 8 gallons of capacity, 1 bushel of pride dried shelf maze weighs 56 pounds. Think about 70,000 bushels. The mandan wife accommodated the unpredictability of north dakotas climate and all but the most dire circumstances. The 21st21st century archaeology is beginning to reveal the extent of the mandan success. Hightech imaging of sites in the harp river area have shown that several towns were major population centers, double ditch village, just north of bismarck run, north dakota, may well be the most spectacular and accessible example. The towns name referring to the most striking visible feature, these two clearly discernible fortification trenches that still delineate forward boundaries of the policy to town. When you look at an image like this you think of a fortification trench that is probably originally six or 7 fer 60 feet across, and on the inner side think of a palisade of sharpened sticks stuck in libya. Now, it turns out that the name double ditch is misleading. What appears to be the outermost trench year does not mark the outermost boundary of the town. Scans completed in 2004 revealed to2004 revealed two additional trenches beyond the two visible ones for a total of four. What this means is that in its spatial dimensions double ditch was once much larger than scholars have recognized. Survey suggest another nearby town a few miles north of double ditch, town called arson also had two additional fortification trenches detectable primarily through magnetic radiometer he. Also much bigger than scholars had imagined. Now call patterns of expansion and contraction differ from village to village, and i, and i am sure that future scholars will add new discoveries. I am sure they are going to surprise. For now, however, it is clear that the mandan, in their heyday, lived in as many as 21 different villages near the missouri harp river confluence. Some of these villages had very brief occupations, but at least six were socalled traditional villages, very large, fortified settlements that lasted into the 17 hundreds. So how many people live hear . Well, it seems likely that a harp river town numbered as many as 15,000 in population at the pinnacle. Pinnacle. This would have been probably around the mid 15 hundreds. And then in the late 15 hundreds something happened. The villagers abandoned those outer to ditches. And they are town shrank to 15 acres. Approximately a 20 percent reaction in size. So they contracted, in other words, into the confines of the outermost to ditches that our eyes can discern today. Now, why did this happen . What cause dash to dwindle in size in the late 15 hundreds . No europeans had arrived, at least in the middle of the continent. But sanitation may have become a problem as population densities increased. Or mandan members may have overwhelmed the carrying capacity of the land they occupied. Or, perhaps, they encounter drought. Drought was widespread throughout the 15 hundreds, and it hits the upper Missouri River with particular force between 1674 1574 and 1609. The repercussions of drought, even the mandan themselves had enough food to sustain themselves through these hard years. The drought may have made them the target of raids by other peoples. They had these permanent villages, a food supply cash because of this, mandan towns were always tempted targets. Now, another hazard of drought is the grasshopper. Stillstill the main a prairie farmers today, and grasshoppers proliferate in dry conditions. Agricultural scientists, one harvest progress upper numbers can double, triple, quadruple with each successive year drought. Now, it is possible that the that because the population collapse was not passed but petulance. Far to the south wave after wave of sickness spread north out of mexico in the aftermath of her non cortez is smallpox assisted conquest of the mushy peers were the aztecs and 1521. There were at least ten severe epidemic episodes between 1531 and 5095. So these are infections like smallpox, measles, influenza. These are viruses from the other world carried by europeans and africans to the americas. The question is, whether these contagions reached the upper Missouri River during the 15 hundreds. Now, interestingly the 1st european trade item would have been a sparse handful of glass beads, maybe two iron implements, the 1st european trade items appear in mandan theological sites right around the year 1600. Almost exactly the same time that the double ditch population collapsed. Logic suggestscollapsed. Logic suggests that knew trade item the new contagions might have arrived around the same time now, uncertainty dissipates with the passage of time, by the early 17 hundreds, their life was in a people again to do the arrival of the horse, another new species to the americas. The horses really reintroduced. And place peoples embraced horses after new mexicos pueblo revolt of 1680 made them more widely accessible, and horses then spread northward through the 17 hundreds. Mandan probably got there 1st horse around the year 1740. Horses, as you can imagine, make more frequent interaction between peoples than ever before. And back in the great plains in the absence of the horse, the pedestrian area, horses meant more frequent interaction. They also hold or carried much more than dogs were humans ever could. They carried trade items. Food. People. Teepees. But they also carried invisible cargoes, news, information, and sometimes people infected with microbes. In the equestrian era of the 17 hundreds and 18 hundreds, Infectious Disease became rampant. Smallpox or some other illness afflicted the Northern Plains peoples and 1730s. And among those who suffered with the lakota sioux rating and trading among the upper missouri villagers. The winter town marks the winter of 1734 dash 35 with the figure wearing an overlay of dots like those used to designate a smallpox