On the A7 motorway at the "Oy-Mittelberg" exit, take the B310 towards Wertach and Oberjoch. There follow the signs for "Tannheimer Tal" B199 until you reach Haldensee. From the Tyrolean side via Reutte on the B198 towards Lechtal to Weißenbach, over the Gaichtpass along the B199 to Haldensee.