- Found in 1973 by Groupe Spéléo Alpin Belge under the name T3, but not pushed to any depth.
- Rediscovered in July 1976 by J.M.Piron and explored from 12th to 23rd of July by A.C.Toulon, S.C.Toulon, Lou Darbon & Spéléo Ragaie to a depth of 708m. Later sources refer to this group as 'an unheard of group of "Spéléos Provençaux"'.
- The same group in 1977 discovered the two lower entrances, using them to explore to the bottom at -913m.
- The Austrian expedition of 1985 set out to connect Feuertalsystem to Raucherkarhöhle and found a large horizontal passage, but no connection.
From the Quelli
entrance, pitches p8, p19, p83, p33, p24, p17, p5, p33, p24, p9, p33, p27, p103 lead to -400m. Here one reaches a vast passage going up and downhill. The downstream passage emerges at the top of an 84m pitch. Below this a winding canyon interspersed with small pitches gives onto a 15m pitch and the end of exploration in 1976 at -708m.
The lower entrances lead by large phreatic passages to pitches which drop into a further large horizontal level which undulates between -410m and -500m. At -497m, this links to the main vertical system from Quelli. Using these lower ways in, exploration reached a sump at -913m in 1977. Following the large phreatic level away from Quelli goes for about a kilometre before breaking into the side of a colossal shaft at -414m. This is a 211m pitch to a choke at -625m. There is a possible way on across this shaft, which is, however, 20m in diameter.
- (GSAB) Spéalp 1 (June 1977) pp 33-49, Totes Gebirge: Description des principaux gouffres de la zone ouest du massif, Jean Claude Hans & Etienne Degrave
- (GSAB) Spéalp 2 (1978) pp 66-67, survey, Feuertalsystem, Jean Claude Hans
The description is translated mainly from these references by Andy Waddington and Jill Gates.
- The Austrian expedition of 1985 found a 3km horizontal passage, which brought the total length of the system to 15km.
- In early 1997 the length was given as 19808m (Markus Wiesinger, personal comm.)