The upper portion of the river has been contaminated to some extent by the operation of a lead smelting plant located near the Kirkland community that recycled used automobile batteries from the 1950s until the 1990s.

They used black-powder blasting techniques to build a diversion tunnel to power the mill, which Bell called "Pattison Forge" (often spelled, incorrectly, "Patterson") after his mother's maiden name.

Also at the "Narrows of the Harpeth" is a prehistoric site known as Mound Bottom, noted for the complex earthwork constructions built from 950 and occupied into the 15th century.

A few miles above the mouth are what are known as the Three Islands; the U.S. Army Corps of Engineers proposed siting a dam near this location on several occasions and did some preliminary study.

[citation needed] The lower portion of the Harpeth is very popular with canoeists, supporting canoe-outfitting and related businesses.

After the removal of the lowhead dam in the city of Franklin, the Harpeth is Tennessee's second-longest unimpounded stream (the longest being the Buffalo).

[13] Hicks does not offer the claim that this is the definitive origin of the name however he does say it is “certainly appropriate…I submit it as the most probable and ingenious theory I can suggest.”[14] Early 18th-century maps including Matthew Carey's 1795 Map of Tennessee[15] as well as that of John Reid,[16] Imlay's American Topography, Arrowsmith, and Stockdale use the spelling Harpath River which differs from the modern spelling of “Harpeth”.

[18] In addition, contemporary historian Virginia Bowman gives credence to Hicks' theory in her comprehensive book on early sites and homes of Williamson County, Tennessee.

[19] There is no dispute that the title of the song "Harper Valley PTA" by Tom T. Hall is derived from this stream, indirectly.

[citation needed] Common put-ins/take-outs: Kingston Springs, TN - An area for canoe access in Cheatham County, west of Nashville.