The southern boundary of Lechquellen Mountains runs from the alpine town of Bludenz along the Klostertal to the Flexen Pass. From there, it continues in the east via Zürs and Lech and along the Lech to its confluence with the Krumbach. The Krumbach forms the boundary of the range in the north up to the Hochtannberg Pass. From there, it runs along the Seebach via the village of Schröcken and continues along the Bregenzer Ach stream up to Au and its confluence with the Argenbach. Then it goes up the Argenbach until just before Damuels and continues along the Faschinabach in the west to the Faschinajoch saddle. From there it descends into the Große Walsertal and along the Lutz to its confluence with the Ill. It then follows the Ill back to Bludenz.