Two million years ago, ancient Ohio’s landscape was dominated by a mighty river that rivaled the majestic Nile in length and grandeur. The prehistoric Teays River flowed nearly one thousand miles from the heart of Appalachia to the Gateway to the West, with wavy ribbons of tributaries fanning out like the fronds of a fern unfurling from the stem.
Its headwaters were the streams that drained the newly formed Appalachian Mountains. The channel they carved stretched from the Blue Ridge in North Carolina, flowing northerly across Virginia into West Virginia, cutting across the tip of Kentucky, entering Ohio at Portsmouth and taking a sharp northerly turn to Chillicothe, cutting cross-country to the vicinity of modern-day Grand Lake St. Marys, then moving westward to Illinois, dipping south to St. Louis, Missouri and emptying into an ancient northern arm of the Gulf of Mexico that once extended into what is now southern Illinois.
Amazingly, this swift-moving watery ancestor of the Mississippi and Ohio rivers disappeared two million years ago after losing the battle with lumbering sheets of ice. Although it is long gone, the Teays River still affects life today. Its deep ancient bed filled with sand and gravel now yields abundant fresh water from wells. Many communities lying atop the buried Teays River channel tap into sand and gravel aquifers several hundred feet below ground for their municipal water supplies.
The extinct Teays River is credited with boosting the biological diversity of southern Ohio, and isolating rare populations of cave crickets. Shawnee State Forest harbors small isolated patches of several Appalachian plants far to the north of their native ranges that are believed to have hitchhiked downstream on the Teays from their North Carolina habitat before the Ice Age. Populations of the Ohio cave beetle and Kramer’s cave beetle in Adams County, which are endangered species in Ohio, are the only known specimens north of the Ohio River. These beetles were most likely stranded in Adams County caves when the interconnected cave systems of Kentucky and southern Ohio were separated after the Teays River dramatically changed course.
Where did the Teays River come from and where has it gone?
In our comfortable mid-continental home, earthquakes and erupting volcanoes, surging seas and melting glaciers seem like the types of natural disasters that befall distant, exotic locales. Through geologic time, though, these violent forces have shaped the gentle Ohio landscape we know today. The firmly planted, solid ground we take for granted isn’t actually as solid or as firmly planted as it appears. The land and water on earth’s crust lie atop rigid plates that float and drift over the hot, plastic layer above earth’s mantle. More than a billion years ago, the seven continents so nicely distributed around the globe today were meshed into a single land mass surrounded by a single ocean. About 750 million years ago, the crust of this supercontinent began to thin and pull apart into smaller pieces riding on separate plates, initiating a series of cataclysmic collisions that gave rise to mountain ranges and sea beds.
 Through the long Paleozoic era from about 570 million years ago, Ohio alternated between tropical sea floor and sunny coastline as water advanced and retreated for more than 300 million years. The often muddy conditions were ideal for the creation of fossils from the hard shells of corals, clams and their cousins as well as the bones of primitive fishes that came later.
Ohio lay near the equator when the continental land mass (called Laurasia) on which it resided collided with a neighboring continental land mass (Gonwanda, ancestor of the modern continent of Africa) about 250 million years ago to create a supercontinent called Pangea. The collision of the continental plates gave Ohio a good jolt, and the area just to the east underwent such a violent upheaval that massive rock formations were twisted and thrust high above sea level while the crust of the plate shoved beneath melted and began to bubble up through volcanoes. Those uplifted rocks and volcanoes formed the ancestral core of the Appalachian Mountains.
During the Mesozoic era, starting about 245 million years ago, Ohio was high and dry, probably populated by dinosaurs and covered by cycads, primitive plants which resembled palm trees or tree-ferns. There is no fossil evidence, however, because erosion outpaced or erased the accumulation of sediments. Ohio’s restless home plate continued to move and stretch, and about 200 million years ago, the supercontinent Pangea was torn apart. The split resulted in the creation of the Atlantic Ocean and the Gulf of Mexico, and the North American plate began to slowly drift north, away from its equatorial neighborhood.
 The formation of the Teays River took place about five million years ago during the Tertiary period of the Cenozoic era, after the age of the dinosaurs. Tucked away securely inland, and no longer buffeted by waves or crashing continents, the plains of Ohio and the craggy peaks of the nearby Appalachian Mountains were most profoundly impacted by the power of running water.
Extensive systems of streams began to carve the mountains and dissect the plains, eventually cutting the great winding channel of the Teays River. Obeying its natural tendency to seek lower ground, the water flowed south to north, east to west until it found its ultimate outlet in the young Gulf of Mexico, which had lapped up over several southern states in a thick finger that traces today’s Mississippi River channel. Over time, the Teays River widened and deepened its channel, and at the height of its glory, the sprawling watercourse varied from one to two miles wide, with depths ranging up to 500 feet deep.
The heyday of the Teays coincided with the rise of the mammals during the Pliocene epoch at the tail end of the Cenozoic. By that time, Ohio had drifted into temperate latitudes, but the climate was still warmer than today, with little seasonal variation. Although the fossil record from this time period is sparse, we do have some clues about life along the Teays from ancient pollen grains found in the Teays valley sediments, as well as archaic bones dredged from a sinkhole in Indiana. The lush banks of the Teays would have been lined with a variety of complex flowering plants resembling the deciduous trees, shrubs and grasses we know today. Beside the oasis was a mix of prairies and forests that would have hosted an incredible array of wildlife. Herds of the ancestors of today’s grassland grazers, like zebras and horses, shared the savannah with camels and rhinoceros. Fabled creatures like sabertooth cats, giant bears and mastodons would have dwelt nearby in the forest primeval.
The demise of the Teays started almost two million years ago at the dawn of the Pleistocene era when, in response to the cooling of the earth’s climate, continental glaciers slowly migrated south from Canada. When the mile-thick glacier reached the vicinity of present-day Chillicothe, it acted as an enormous dam that blocked the flow of the Teays and flooded the area. The result was a large lake, 900 feet deep and 7,000 square miles in area (nearly two-thirds the size of Lake Erie) in parts of southern Ohio, Kentucky and West Virginia. Lake Tight (named in honor of the Denison University professor William G. Tight, who studied the Teays in the late 1800s) served as an Ice Age watering hole for about 6,500 years. The waters of Lake Tight continued to rise and eventually overflow, forming deep new drainage channels which, in some cases, directed the flow of water in the opposite direction of the original Teays River.
 One lasting remnant of this vastly altered landscape in southern Ohio was the newly created channel of the Ohio River. After the advance of the initial (Nebraskan) glacier that blocked the Teays River, three additional glaciers advanced and retreated over the course of more than a million years, covering two-thirds of Ohio with ice. In addition to flattening the landscape in places and leaving mounds of debris in others, the later glaciers further modified drainage patterns to the northeast and southwest, establishing the headwaters of the young Ohio River in western Pennsylvania, and carving the channel in its present location with southwesterly flow.
When the last of the Ice Age glaciers (Wisconsinan) finally retreated from Ohio, the Ohio River was flowing free while much of the old Teays River valley was buried under sand and gravel, several hundred feet deep in places.
Beyond the reach of the glaciers, the remaining Teays River channel was abandoned or commandeered by new rivers. In the Appalachian region, including the southern leg of the Teays River in Ohio, the old river valley is still a prominent landform that is visible from the air. The story of a lost goose provides anecdotal evidence that migrating birds may recognize the ancient river channel as a landmark on their flight path. Birders speculate that a Ross’s goose (a western species that is rarely sighted in Ohio) that was forced to land in Jackson County during a December storm several years ago may have mistaken the footprint of the Teays River valley for a major contemporary waterway.
The Teays River may hold some secrets that are yet to be discovered. Much of what we know about the Teays, including its precise course 1and probable fate, has been deduced from examining the depth and composition of sediments in glaciated areas, and piecing the results together with the visible evidence in unglaciated areas. Whatever future discoveries unearth about the mighty Teays, its legacy will certainly continue to enrich life along Ohio’s ancient Nile.
-Jean Backs, Editor
1Some experts believe that the Teays took a different course from Chillicothe, flowing northeasterly across Ohio to an ancient waterway named the Erigan River, which flowed through the area now occupied by Lake Erie.
Thanks to Mike Hansen, director of the Ohio Seismic Network and retired Senior Geologist for the ODNR Division of Geological Survey, for his assistance in compiling this article. |