A vocabulary of landscape — a landscape of words 1053 entries

freestone

FREE-stohn
A river or stream fed primarily by rainfall and snowmelt rather than by springs or dam releases. Freestone streams are wilder and more variable than tailwaters — their flows rise and fall with the weather, their temperatures fluctuate with the seasons, and their character changes year to year. The word implies independence from human infrastructure and is mostly used by anglers.
Etymology
Originally a masonry term for stone that can be cut freely in any direction. Applied to rivers, it suggests water that runs free — unregulated, undammed, subject only to weather and gravity.