The Mississippi, like most rivers, was formed when ice began to melt ending the Ice Ages. As the glaciers receded, they carved large troughs in the earth's surface carrying the melting snow and ice, as water, to the sea. Over the millenium, silt from the upper regions of the Mississippi would deposit themselves as sand barges further downstream. Most but not all of the sand barges would be carried further downstream and deposited at sea level close to the river's mouth. Force from the river waters would continue gouge the soft soil to make the Mississippi Delta.