 It is 100 km long.The river's headwaters are in the "reculée" (blind valley) of Baume-les-Messieurs, approximately 10 km east of Lons-le-Saunier.From there it crosses the vineyards of the Jura department, irrigating the communes of Nevy-sur-Seille, Voiteur, and Arlay, before reaching the agricultural plain of Bletterans.