“Take any natural process, however slow it might appear, and give it enough time, and it would add up to profound change.” -Charles Lydell, Principles of Geology. Looking at any relief map of the Middle Mississippi reveals the ancient flow of the big rivers in their rampage through middle America following the melting of the Canadian ice cap. You can see it on USGS topographic maps, or DeLorme’s Atlas. Heck, you can even see it on Google earth. And what’s more, it becomes radically enlarged at present day St. Louis where the big rivers come together. Forgive me this side channel, but it helps explain the present day geography of the Middle/Lower Mississippi alluvial valley.
Several thousand years ago this confluence was a mad conflagration of glacial meltwater, with the retreat of the Laurentide Ice Sheet, each of the big three rivers the Missouri, the Illinois, the Mississippi, twenty to thirty times their present sizes, each barreling down their respective valleys with destructive chaotic madness and smashing into each other in the present vicinity of Portage De Sioux, the Upper Mississippi passing present day Hannibal at ten to twelve miles and hour and filling its valley bluff to bluff, a four mile wide madcap of fast whitewater, the 2-mile wide Illinois slamming in sideways from the northeast after being squeezed through the limestone cliffs and bluffs which narrow above Grafton, the collision of water was a monstrous confusion of converging channels with ten-foot tall standing waves chaotically ricocheting off one another in choppy convoluted patterns, a scene that would make today’s lava falls of the Grand Canyon look like child’s play in comparison. This jumping mass of ice cold glacial waters swept across Portage de Sioux completely submerging the flatlands as the waves rebounded back and forth and the variegated channels surged past one another creating powerful eddies and deadly whirlpools that sucked down giant bison, wooly mammoths, saber toothed tigers and sloths, and even the 500 pound beavers of that era would not be able to negotiate. To think of crossing would be madness, suicidal, even for the best swimmer. Only the strongest fish could handle these waters. All others were swept away or drowned. The megafauna kept to their respective sides of the river, and only found connections hundreds of miles upstream where things were calmer and the waterways narrower, maybe a mile wide instead of five.
The combined Upper Miss/Illinois now swept across Portage de Sioux in a crashing, rolling mass full of gravel, rocks, boulders even, roaring over the sudden shallows that now are the fertile bottomland fields downstream of Old Monroe, past St. Charles across Orchard Farm and down past Alton to the present day location of the confluence, at the point of the St. Louis bulge. The waters calmed slightly as they widened and flowed over the shallows, but also any waves were attenuated in the shallow waters, and so what was a ten foot wave in deeper water might rise to fifteen feet and crash over in repeated arrays of foamy waves several miles wide, something like the present day Pororoca of the Amazon, that must have appeared and disappeared in seemingly endless fields of foamy white waves, responding to giant fluctuations of water volume. And then an even louder and madder roaring could be heard further to the south towards the rising bluffs now inhabited by greater St. Louis. A two-mile wide tongue of sediment laden brown water rocketed out of the Missouri valley, past the short rise that St. Charles now sits, with the Florissant Bluffs (St. Louis) to the south and smashed into the ten mile wide Mississippi with greater force and madness than the Illinois had further up. It was the Missouri, reaching far to the west, thousands of miles. The Missouri River was considered the leading edge of the Canadian Ice cap, and the Canadian ice cap in its entirety was as large as present day Antarctica. So the Missouri probably carried more water volume than all the others, collecting all of the melting ice water and great plains sediment from the Rocky Mountains downstream, a two thousand-mile long funnel, and when it reached the present day bluffs at Kansas City, and was thrust across what is now Missouri, to go swirling and whirling back and forth and up and down, and all ways imaginable within the five mile wide floodplain, when it flowed into the last bluffs at present day St. Charles, it all was concentrated into this one opening, and then exploded, as it were unleashed, it hit the Mississippi with unimaginable more impact than any other confluence of rivers ever experienced in the Americas north or south. Water flow at St. Louis might have approached 5 million CFS at the height of the ice cap melt, and 15-20 million CFS below the mouth of the Ohio, something like the present day flow of the Amazon River as it flows into the Atlantic Ocean.
The engorged Missouri smashed into the Mississippi with the violence of stampeding herd of bison and shoved the waters back rolling and tumbling across the countryside across Portage de Sioux, and like all rivers the mixing was angry, violent, uneven, waters mashing, smashing and swirling this way and that, the Mississippi darker greyer perhaps, the Missouri browner, redder, oranger, the demarkation line between the cold colors of one and the warmer colors of the other etched far downstream over the thick waters. The combined waters must have seemed unstoppable, and they were for several dozen miles as they raced across the top of the American Bottom -- until the Illinois hills reared up and the unavoidable force of gravity curved them on themselves in more collisions of water wild bucking channels, and made them come around on themselves to turn one hundred and eighty degrees around the rocky bluffs of St. Louis, and then even further, another quarter turn, two hundred and seventy degrees in all, until the most angry tongue of water ever seen before and seen since responded to the unassailable force of gravity to collapse over themselves, and be forced by the dolomite bluffs at the edge of the American Bottom on the east and the rising bluffs of River Hills of Missouri on the west, to be molded into one sinuous single channel, all the waters of all three rivers now squeezed together into the three-mile wide opening below what is now the JB Bridge, and then explode outwards in the more expansive valley below, to go rocking and rolling dozens of miles down the gently eastward curving valley scouring out everything in its path, and then getting squeezed again further down at Grand Tower, the excess bursting behind Fountain Bluff to accommodate the flow, the conflagration opening up again below in the wide valley below Trail of Tears, but then squeezed again where the Pawnee Hills bisect the valley below Cape Girardeau, an eruption of flow burst out of the mass to flow westward in a depressed lowlands at base of the Ozark Hills westward. to explode out and around both sides of Crowley’s Ridge and on down into the Mississippi Embayment below, which was once an inlet of the Gulf of Mexico, but was refilled with glacial sediment as result.
If I could be anywhere I wanted to be in the history of the earth, one of them would be on top of the Rock of Gibraltar when the azimuth broke open and 40,000 times the Niagara Falls broke into the desert rift between Europe and Africa and filled up the Mediterranean Sea. The other would be on top of the bluffs at present day Jefferson Barracks watching the glacial melt fill the Middle Mississippi Valley, or maybe on top of the Fountain Bluff down near Grand Tower, or maybe at bluff at Thebes watching the waters crash with violent crescendoes through these narrows. This scene would have looked something like the 1993 flood from the distance, but up close even that flood, the worst ever in recorded history, would seem calm and friendly compared to the gargantuan thrashing waters at the height of the glacial meltdown. If you multiplied Lower Congo River Waterfalls near Kinshasa 20 times this would hint at the scale of chaos that roiled this juncture of compression where the American Bottom narrows in half as the Illinois Bluffs approach the Missouri Bluffs below present day JB Bridge near Waverly Missouri. (PS: The Congo River is the most powerful river in Africa. During the rainy season over 1,800,000 CFS flow into the Atlantic Ocean, and alone accounts for thirteen percent of global hydropower potential.)
Adventurous History Buffs who want to re-live the river of those days should wait until the big river has dropped below 10 on the St. Louis Gage and hire Big Muddy Mike for a thrilling run over the Chain of Rocks in one of his big canoes, and then try to imagine this half-mile wide cauldron of crashing thrashing waves, keepers, boils, eddies, whirlpools and general water mayhem multiplied 40 times, adding on another 20 channels about the same size, and a one or two bigger, and hundreds of smaller rip-roaring channels in the braided tapestry of the melting glacier water.
Present Day Middle Mississippi
But let’s leave the thrill of riding those rapids through the ice age behind and fast forward a dozen thousand years or more to the present day and age where paddlers enjoy an entirely different river, although it can at times and at certain water levels and certain places resemble the river of yore.
Today’s experience on the river is radically different than what bison and saber tooth tigers encountered 15,000 years ago when it was all about survival. Expeditions on the Mississippi River today draw you into long-distance journeys of the heart, where you travel through a landscape and are changed by it. The journey by canoe becomes a metaphorical journey in the discovery of the self. And this is the greatest good, according to the Socrates, and concurred by Jesus in the New Testament. As you bob along downstream dodging buoys and towboats, you become inevitably disturbed by scenes and natural occurrences that cause you to wonder, the wonder sets off a chain of events in your imagination that might go through layers and layers of self-realization that might begin with confusion, maybe fear, maybe even terror, then back to wonder, eventually to resolve itself in realization, maybe comprehension or compassion, and then you either find yourself enlightened with some new knowledge or new appreciation, or you accept the wonders of the creation as work of the creator, and are filled with joy of experiencing beauty of the creator in everyday expressions of sand, mud, water, trees and sky, and the creatures that inhabit them.