Riverfolk

The Riverfolk weren't always waterborne traders; they were once part of a much greater clan of caravaners trading along the route between the City of Pensan in the far west, and Aberston to the southeast of the Bellever Mountains, via the Tremenydh Pass. Other routes included branching from the westward end of the pass southwest through the Pensan Rainforest to the Shark Tooth Isles and northeast from the eastward end towards the Tewledandar Forest, before circling around the Kermendyowl Moor incorporating the great plains to the east and the Du Kerreswik Hills.
The great avalanche that blocked the Tremenydh Pass not only cut Tamaria off from Aberfal, but a small yet powerful traveller family off from the rest of the clan. After several attempts to clear a path through the debris failed, despite the increasing number of caravans congregating at the eastern edge as they made their return journeys to Aberfal.
Although nomadic in nature, preferring life on the road, the traders considered Aberfal to be their homeland, tracing their lineage back to the ancient nomadic peoples of the Bodmany Desert. Though unaccustomed to prolonged exposure to the temperate climate of Tamaria, and with no goods to trade from the west, they leaned into their collective knowledge gleaned through years of trading with various cultures, and identified a new need that they could meet: large-scale trade between the Dwarven Houses and Aberston; currently trade was only via road-caravans, with small quantities of the heavy ores loaded onto trailers.
By constructing rudimentary rafts, they were able to ship much larger quantities of ore at a reduced cost along the River Glanwyn, and so the River Folk came into being.