Let's face it, the world is a unique place. For example, there is an underground river about 200 feet below the Tuscarawas River, in Massillon, Ohio. Yes, there is such a thing. It is the pre-glacial and inter-glacial remnants of the ancient Dover River.
Stout's (1943) Map of the Teays River Stage features the Dover River (p. 50).
An unidentified newspaper article titled, "There's water under Tuscarawas River, but it moves quite slowly" explained that the underground river is a result from "pre-glacial and inter-glacial water movement that eroded a channel into the bedrock (1966). In fact, the Dover River was also responsible for carving out the Cuyahoga Valley (Harris, 2004, 181). The river flowed from Cuyahoga County where it branched out into parts of Summit, Portage, Stark, Carroll, Medina, Tuscarawas, Harrison, Columbiana, and Belmont counties (Stout, 1943, 71).
Over time, the ancient river channel now below the Tuscarawas River became filled with silt, gravel, and sand. These layers of silt, gravel, and sand filling the channel are also known as an "aquifer," which causes the river to move only a "few feet per day" (1966). When the Dover River experiences periods of drought or water pumping from nearby industries the direction of the river could reverse (1966). The river came to an end during the time of the Pleistocene glaciation or Pleistocene Epoch about (2 million - 10,000 years ago) (Stevens, 19991, 15).
To learn more about the Dover River check out these resources.
(1966). "There's water under Tuscarawas River, but it moves quite slowly." Massillon Public Library Vertical File: Massillon Water Supply.
Harris, A. G. Tuttle, E., & Tuttle, S. D. (2004). Geology of national parks. (6th Ed). (Vol. 1). USA: Kendall/Hunt Publishing Co. Retrieved June 21, 2011, from Google Books.
Stevens, W. (1991). Ground water pollution potential of Stark County, Ohio. (Report 6). Ohio Department of Natural Resources. Retrieved June 21, 2011, from DNR.
Stout, W., Ver Steeg, K., & Lamb, G. F. (1943). Geological survery of Ohio: Geology of water in Ohio. (Fourth Series, Bulletin 44). Columbus: F. J. Heer Printing Co.