Wilderness Road Through the Wetwoods

THE WETWOODS. Between Louisville, Ky., and old Deposit Station, on the line of the Louisville and Nashville R. R. there is an extensive basin lying at the foot of the Knobs, known as "The Wetwoods." It has been noted not only for its wetness, but for the lawless character of its inhabitants. A system of drainage, however, has not only improved the land, but the morals of the people, and one may now pass through it in safety, although the old lawless spirit will show itself occasionally in deeds of murder and violence. During a residence of five years in Louisville I have taken many a weary journey through that section of country trying to solve the problem of its origin. At first it seemed if the great continental ice-sheet, or spurs of it, must have scooped out the basin in question, and also rounded out the adjoining knobs into their peculiar contour, but subsequent investigation has led me to abandon this view, although glaciers doubtless played some part in it. A close examination of this region shows that the basin itself is indented with numerous channels that seem to correspond with the breaks in the hills. Were these at one time connected, and if so, how was this connection broken off? - are questions which naturally suggest themselves.

1879 Jefferson Co Precincts map showing the Wetwoods.

Southeast of Louisville there are two streams - with numerous branches - the Beargrass and Fern creeks. The former joins the Ohio River this side of the knobs, the latter penetrates through them, at least in part, for some of the branches seem to become lost in the Wetwoods. In fact they are really the cause of the phenomenon. In preglacial times these channels had, doubtless, free course, but during the ice age they became obstructed and have remained so until set at liberty by the hand of man. It has been shown in a previous letter to the AMERICAN GEOLOGIST, on Preglacial streams near Louisville, that the mouths of the Beargrass were at one time much larger than at present, which would be the case if they drained the region referred to.

It seems to be evident, then, that this basin is the result of preglacial erosion, and that the Wetwoods are due to the obstruction of these ancient river channels during the Glacial period. When the ice-sheet lay over this region these streams were probably subglacial, and their channels no doubt were greatly enlarged and flooded until partially filled in by the retreating glacier. The summits of the highest hills around Louisville show the effects of erosion; even the tops of the knobs, both in Kentucky and Indiana at the hight of 400 feet are worn and eroded into all kinds of fantastic shapes, and when the clay that covers them is removed the rock looks as smooth as if the water had but receded yesterday. The idea that this deposit of clay covering the rock from four to twenty feet in thickness, is the result of weathering seems to the writer preposterous. It is either fluviatile [pertaining or peculiar to rivers; found in or near rivers] or glacial in character. Quite a large number of sandstone boulders have been collected by the writer, and their position in the clay seems to indicate that they are glacial in origin. The knobs, on both sides of the Ohio river, though much broken, remain as hills where streams have not been large and powerful enough to wear them down to the deeper valleys, like the so called Collett glacial valley in Indiana, which by the way, is a preglacial valley, and was long in existence before the ice-sheet covered it. Both arms of the knobs stretch out from the river for the distance of about eight or nine miles, and both break off in the same peculiar way, like the back of a dromedary between the head and the hump. The cause of these breaks where the knobs disappear is the Silver creek channel on the Indiana side, and Fern creek and Salt river, on the Kentucky side. I have been unable to trace out these ancient channels in all of their former ramifications, and it is doubtful if their connections can be exactly determined, but a close examination of this region under consideration, will convince any one familiar with such phenomena, that preglacial streams acting with the ice-sheet operated in the formation of this basin known as the Wetwoods.

Near Old Deposit station, in the center of this depression is a conical hill, perfectly round, which looks as if it might be artificial, but the sweep of the old channels around it bespeak its origin. It seems to have been the site of an Indian village as great numbers of broken flints and arrow-heads can be picked up on its southern slope.