Geology as Destiny

We first got interested in the fall line while hiking at Great Falls on the Potomac. We learned that the fall line was more than a geological barrier. It had all sorts of societal effects – it determined the location of towns and cities, it affected the distribution of power and wealth, etc. On this road trip, there was no fall line between central Alabama and San Antonio. We’re now headed back east from SA, and have reached the Mississippi delta. Still no fall line, but the point about geology being destiny was hammered home with force yesterday. We drove Highway 61 from central Mississippi through Vicksburg and Clarksdale to Memphis. It’s hot and verdant bottom land, flat as a pancake. We drove hundreds of miles within sight or smell of the Mississippi River, and the only two points where the land is at least 25 feet higher than the river are Memphis and Vicksburg. If you look at a Google maps satellite view, you can see that at both places the vegetation changes, as the hills spilling hundreds of miles from the east come to a halt on the river bluff and give way to the delta. It’s no wonder native Americans and pioneers settled those locations. They were the only flood-proof high ground around. If you have to defend the river, those are the only places you could do it. When you experience the topology, the battle of Vicksburg makes a lot more sense.