The river Simme's spring is on the Rezli alp to the west of the mountain Wildstrubel near the village of Lenk. Underneath the Rezli alp it forms the Simmenfälle, several waterfalls, which have, altogether, a drop of 200 m. Then the river passes Lenk and flows towards Zweisimmen, where it flows together with the Kleine Simme (Little Simme), which flows down from the Saanemöser mountains. It is approximately 10 km long.
From Zweisimmen the Simme flows through the Upper and Lower Simmental (Ober- and Niedersimmental). Near the village of Wimmis the Simme joins the river Kander.