"a tidal river," 1650s; see salt (n. ) + river. as a proper name, it was used early 19c. with reference to backwoods inhabitants of the U.S., especially those of Kentucky (there is a Salt River in the Bluegrass region of the state; the river is not salty, but salt manufactured from salt licks in the area was shipped down the river). The U.S. political slang phrase to row (someone) up Salt River "send (someone) to political defeat" probably owes its origin to this geographical reference, as the first attested use (1828) is in a Kentucky context. The phrase may also refer to the salt of tears.
An undertaker will no longer be known as an "undertaker and embalmer." In the future he will be known as the "mortician." This was decided on at the second day's meeting of the Funeral Directors' Association of Kentucky, which was held in Louisville. [The Medical Herald, July 1895]
[B]y sun-down [the gals] come pourin out of the woods like pissants out of an old log when tother end's afire. ["Dick Harlan's Tennessee Frolic," in collection "A Quarter Race in Kentucky," Philadelphia, 1846]
also rip-roaring, "full of vigour, spirit, or excellence" [OED], 1834, in affectations of Western U.S. (Kentucky) slang, altered from riproarious "boisterous, violent" (1821), from rip (v.) "tear apart" + uproarious; see uproar. Rip-roarer was noted as a nickname for a Kentuckian in 1837. Related: Riproaringest.