Clarksville is located at (36.559383, -87.358261). The elevation is 382 feet above sea level. This altitude can be found on a section of Riverside Drive, which runs along the eastern bank of the Cumberland, but most of the city is higher. Clarksville's civil airport, Outlaw Field, is listed as 550 feet AMSL by survey. According to ''Topo USA'' mapping software, the city square sits at 475 feet and the courthouse at 509 feet. There is a point on the northern side of Memorial Drive near Medical Court that reaches 598 feet. According to the United States Census Bureau, the city has a total area of 247.4 km sq (95.5 square miles). 245.7 km sq (94.9 mi sq) of it is land and 1.8 km sq (0.7 mi sq) of it (0.71%) is water. Clarksville is located on the northwest edge of the Highland Rim, which surrounds the Nashville Basin, and is 45 miles northwest of Nashville. Clarksville was founded on the Cumberland River near the confluence of the Cumberland and the Red River (Tennessee-Kentucky)Red River. The Cumberland flows downstream from Nashville, some 40 miles southeast of Clarksville. From its beginnings, the river was the city's commercial lifeline. Flat boats and, by the 1820s, steamboats carried cotton, oats, soybeans and tobacco, downstream to the Ohio River and up the Ohio to Pittsburgh. More frequently, cargo went ''down'' the Ohio to the Mississippi River and New Orleans. Both dark-fired and burly tobacco are grown in the area, and European tobacco buyers helped make Clarksville the largest market in the world for dark-fired tobacco, particularly Type 22 tobaccoType 22, used in smokeless products. It was considered to have the highest nicotine content of all tobaccos in the 19th century. To the northwest of Clarksville, lies the Fort Campbell, KYFort Campbell Military Reservation, home of the 101st101st Airborne (Air Assault). Much of Clarksville's economy can be attributed to Fort Campbell's presence. Most of Fort Campbell is in Tennessee, mostly in Montgomery and Stewart County, TennesseeStewart counties. It is classified as a Kentucky location because its post office is in Kentucky. Source: http://en.wikipedia.org/wiki/Clarksville%2C_Tennessee