The Kaiser is part of the Northern Limestone Alps and consists mainly of Wetterstein limestone and dolomite. The Wetterstein limestone has a maximum thickness of about 1000 m, which corresponds to the maximum height of the rock faces (Felsabbrüche) of the Kaiser. The younger dolomites are mainly found in the valley hollows. Extensive moraine fields are a remnant of the Würm glaciation. The Kaiser Mountains are drained in the west by the Sparchenbach, which flows through the Kaisertal and later empties into the Inn; in the east by the Kaiserbach, which flows through the Kaiserbachtal and discharges into the Großache which in turn flows into the Chiemsee lake; in the north by the Weissenbach and in the south, in the area west of the so-called Ellmauer Tor, by the Weißache - which also drains into the Inn; and to the east of the Ellmauer Tor (watershed) by the Goinger Hausbach and Rettenbach, both of which flow into the Reither Ache, another tributary of the Großache. Between Fleischbank and the Goinger Halt is a small cirque glacier that will probably disappear soon as average temperatures rise. In the far west of the mountain range is Lake Hinterstein which is used as a bathing lake.