Mile 436.0 LBD — Walnut Hills (Mississippi Loess Bluff #1)
The river dives to over 200 feet as it comes around Delta Point through Centennial Cutoff, forced downward by the Walnut Hills upon which Vicksburg sits. The turbulent action of the water carving deeper and deeper through the Mississippi Mud makes this one of the deepest holes along the entire Mississippi River.
When the water is below 30 in the Vicksburg Gage, horizontal cliff loess cliffs emerge below the City of Vicksburg Riverfront Park at 436.5 RBD, providing a special view into the geology of the bluffs, which is everywhere else covered by trees, vines, and other thick vegetation. From here downstream to Baton Rouge the loess bluffs express themselves to view, and each one is distinct. This first one was named Nogales by the Spanish Pioneers, and is the least colorful of all the bluffs, a monotone grey (except for one splash of color at the very end, a hump of yellow orange, similar to colors seen further downstream). The horizontal layering is probably due to the way the dust settled in layers tens of thousands of years ago after the melting of the continental ice caps. The scouring action of the river has rounded all of the hard edges of the rock, giving it a friendly feel.
Paddlers can pull off into the slow water usually found along the bluffs and get close to this unique topography. Landings are possible on some flat rounded shelves, or in a pile of sand deposited in some alcoves where a loess boulder broke off and created a harbor below. Make a landing and take a walk to get the feel of the loess formation, but watch out for upstream tows whose passing might make big waves along the shore.
The bluffs are best seen below the Riverfront Park at mile 436 LBD (these emerge around 30VG) and a second expression below the bridge at 435 LBD (emerge around 20VG). The second exposed bluffs form broad shelves of rock, sand and mud below 15Vg which would afford a unique low water campsite for anyone needing an overnight directly below Vicksburg. As stated earlier, the best high water camping near Vicksburg would be at Delta Point opposite the mouth of the Yazoo.
Greatest Dust Storm Ever
The Mississippi Loess Bluffs tower above the river the result of massive dust storms that blew across the Great Plains ten thousand years ago and picked up dried sediment off of 22 million acres of dried glacial dust between the Ohio River and the Gulf of Mexico. It was a Great Dust Storm on steroids, millions of acres of pulverized and dried sediment leftover from the melting of the last ice age (when the continental ice cap retreated northward, yielding its great stores of water into a labyrinth of lacerated streams, all twisting and writhing in snake-like mating season fecundity, forming and reforming channels and carving the Middle and Lower Mississippi valleys at the same time, and the Ohio River valley also, the sum of which was twenty times the present volume of the Mississippi, in the same league as the contemporary flow of the Amazon).
Thousands of years of blowing dust borne by the wild winds of the west hit the calming moisture-rich floodplain of the big valley and was brought to rest by the relatively peaceful atmosphere in giant dunes over its eastern edge, all loess dunes are found east of the Mississippi River. And like all dunes they were piled in repeating patterns of big piles and small piles and no piles at all, tributary valleys in between. And like all wave or ripple patterns they left behind a syncopated miasma of big bluffs and small bluffs rising out of the otherwise flat landscape of the Lower Mississippi Floodplain.