The Zugspitze was first mentioned by name in 1590. In a description of the border between the County of Werdenfels and Austria, it states that the same border runs from the Zugspitz and over the Derle (von dem Zugspitz und über den Derle) and continues to a bridge over the River Loisach. Another border treaty in 1656 states: The highest Wetterstein or Zugspitz (Der höchste Wetterstain oder Zugspitz). There is also a map dating to the second half of the 18th century that shows the Reintal in the County of Werdenfels. It covers the Reintal valley from the Reintaler Hof to the Zugspitzplatt and shows prominent points in the surrounding area, details of tracks and roads and the use pasture use. This includes a track over the then much larger Schneeferner glacier to the summit region of the Zugspitze. However the map does not show any obvious route to the summit itself.