Département: Haute-Savoie (74)
Commune: Serraval, Les Clefs
Unité karstique: Massif de la Tournette
Inventaire: TO4, TO11, TO38, TO75, TO81, TO100
Altitude de l'entrée haute: Z= 2060m
Profondeur: 1145m (+53, -1095)
Développement: 11200m
Inventeurs: SCT, SCA
Exploration et topographie: SCA, FALC, SIS
Bibliographie:
Spéléalpes #1,3,4,5,6,7,10,11,12,13,14,16,17,18
Spelunca #76(1976), 58(1995)
International Caver #14p66(1995)
SIS pieds sous terre #1,#2
Speleo #21, 1996
Partial Section: main stream branch
This mountain has always be steep and tough, with caves opening essentially in the 2000m range and above, and a very short summer season. Often many holes are closed by the snow until end of July, and we have seen snow on our camp as early as the middle of August... Currently the deep parts of the system are reachable more or less 3 months a year, and only when we have a perfect weather forecast for the next 3 days.
In 1985, we had connected 5 entrances, and the system was 10kms long; the deepest point was a small but dangerous stream, at -270m. In summer '85, the route to the river was initiated, through the Prad'zheures entrance, but it took us 10 years to reach -500. Between '93 and '95, though, we were much more successful, finaly establishing a deep camp at -580, and reaching -1096 at the end of 1995. And the cave is still going: we are still 300m higher and 5kms afar from the spring.
After several years of digging just in the middle of our camp, at Z=1680, we finally have open in 1999 a new cave that could be the shorter route to the bottom. It's numbered TO100, depth -400m, and not yet connected to the system.