The Gruberhorn (1732 m) is the middle peak of a striking trio of summits along the main ridge of the Osterhorngruppe, easily recognizable from as far away as Faistenau. Flanked by the Gennerhorn to the east and the Regenspitz to the northwest, it rises above the village of Hintersee.

To the north, the mountain drops away in a massive, steep grassy flank cut by gullies and ravines, falling toward the Gruberalm. Below the summit you can clearly see the horizontal banded limestone layers typical of the whole Osterhorngruppe. The slopes are covered in mountain pine, with narrow gaps threading through the thickets. From the top, the view stretches to the Dachstein massif, the Gosaukamm with the Bischofsmütze, and the Tennengebirge to the south, the Untersberg to the west, and the Kolomannsberg, Schober and Faistenauer Schafberg to the north.

• Genneralm (1295 m) — reached via a toll forest road from the Lämmerbachtal valley, moderate difficulty, the path leads past the Gennerhorn to the saddle between Gennerhorn and Gruberhorn, then follows the east ridge to the top
• From the south via the Hintertrattbergalm over the Hohe First and Dürlstein, connecting with a section of the Arnoweg
• The narrow, exposed northwest ridge links Gruberhorn with the Regenspitz, with the Bergalm (1250 m) as a base to the west

• The Genneralm can be reached by private car via a toll forest road
• There are no marked trails across the flanks — routes follow the ridges only
• A steep step on the east ridge is surprisingly easy to overcome

The panoramic view from the Gruberhorn is one of the finest in the Osterhorngruppe, and the horizontal rock bands visible on its slopes are a real geological trademark of the region.