The story
From fiber + shed, modelled on watershed. Came later than various others on that pattern such as milkshed and foodshed. Seems to have been coined by founder of fibershed.org Rebecca Burgess in 2011.
Etymology from Wiktionary, CC BY-SA 4.0.
fibershed
Today it means: The geographic region from which come all of the resources to make an article of clothing. Full definition →