The valley was formed during the Würm Ice Age by the Reintal Glacier and then deepened by the Partnach in the post-ice age period after the retreat of the glacier to the periphery of the Schneefernerkopf mountain. The upper Reintal, which was shaped by the glacier and today forms a U-shaped glacial valley, ends between the Hohe Gaifkopf in the west and the Schachen in the east. The lower Reintal lies in the area of the former glacial lake of the Loisach Glacier, into which the Reintal Glacier flowed from the southwest. It is a V-shaped valley and has been predominantly shaped by the Partnach river.