Jager Couloir is located to the right of Gervasutti Couloir and left of Albinoni-Gabarrou Couloir on the north-eastern aspect of Mont Blanc du Tacul. It was first climbed by Pierre Barthelemy and Claude Jager in June 1964. Although slightly steeper than Gervasutti Couloir the Jager Couloir is generally safer due to the absence of any seracs at the top of the route. The route is fairly popular both in summer and winter although receives less traffic than Gervasutti Couloir.
The base of the route is most easily reached from the Chamonix side. Take a cable car from Chamonix to the Aiguille du Midi station. From here or from the Cosmiques hut head south across the Col du Midi skirting the northern-eastern aspect of Mont Blanc du Tacul. Jager Couloir is the boomerang shaped coulier to the right of the obvious Gervasutti Couloir. From the Cosmiques hut the base of the route can easily be reached in under 1 hour.
It is also possible to reach the route from the Torino hut or the Bivouac de la Fourche. The main disadvantage of approaching this way is that the walk-out will be long following descent to the Col du Midi.
The couloir averages 55 degrees and 600m in length. The route is obvious although longer than it appairs from below. An early start is mandatory due to the immediate exposure that the route receives from the sun. There are no mixed sections. The steepest section (60 degrees) is found towards the start of the climb although climbing gradient is fairly uniform for the couloir's entirity.
Around 1/3 up the route the Korean Pillar route (TD-) starts to the right up a steeper couloir.
At the top of the ice couloir there is a small ice step which should not pose too much problems and the cornice was easy to avoid when I climbed the route. Descend via the NW Flank. An alternative direct finish is also possible. Climb up one of the two gullies branching off left to finish the route via two mixed pitches to reach a secondary ridge.
Limited equipment is required. If you wish to climb in pitches then some snow stakes may be useful. There are limited rock placements along the side of the couloir.
Ice screws may be useful in good conditions.
The route is most suited to climbers comfortable to move together either roped up or soloing however.