For the south approach you have to follow the road until Matrei, then the Virgental to the end of the valley to the village Streden, 1403m where there is a parking place. You have to pay 3 euros for one day or 9 euros for one week.
From the parking place you must reach the hut Essener-Rostocker, 2208m over the long valley Maurer Tal. The route is well marked. You will need from 2-3 hours to the hut.
From the hut you follow the signposts for the Grosser Geiger. From the hut you go in the north direction. First you cross the crossing with the route to Simonyspitze, 3488m and then alsothe crossing with the route to the hut Johannis hütte, 2121m. You continue over the big and very long valley to the north in the direction to the notch MaurerTörl, 3108m.
The valley is very beautiful and you will enjoy on the wild view to the seracs of the glacier Maurerkess. When you come to the end of the valley you will start ascending on the big moraine. Be carefulon some holes in the moraine. The climbing over the big rocks is tiring. It is easier and quicker if there is more snow. After this part of the route you will come to the start of the glacier just below the south face of the Kleiner Maurerkeeskopf, 3205m. Here you start a long crossing over the glacier full of crevasses all the way to the southwest face of Grosser Geiger.
When you come below the upper face of Geiger above the glacier you have three possibilities for climbing to the top.
The first one goes up over the west ridge that you reach it over the steep SW slope. The second one goes directly up SW slope and face to the top. It is more appliable in good snowy condition. The third possibility is to climb to the top over the south ridge. For the third possibilty you must reach the pass between Grosser Geiger and Grosser Happ, 3350m and then you climb to the top over the south ridge.
All three possibilities have similar difficulty. You will need around 4-5 hours fromthe hut for the ascent and around 2-3 hours for the descent.
Essential GearIce axe, ropes and crampons are necessary because the glacier is full of cravases.
With ski, most mountaineers don't use a rope, but everyone has to decide this on his own.