The phisycal systems of Papoose Cave: an alpine cave in West-Central Idaho, U.S.A.

Papoose Cave is located in the Seven Devils Mountains of west-central Idaho in the northwestern United States. The cave is at an elevation of just over 1500 meters in these steeply sloping, glaciated mountains. Papoose Cave drops over 250 meters in depth and has over 4,000 meters of known passages.

While it is one of the deepest caves in the United States, it does not make the list of world class caves. Low temperatvres (about 2'C), vertical drops, and considerable water make the cave a challenge.

The cave is essentially a joint-controlled system with a subparallel rectilinear pattern, extending downward along the regional slope which is also nearly parallel to the southeast dip of the metasediments. The cave is in the lower units of the Martin Bridge Limestone, a marine deposit of late Triassic age.

After minor phreatic development, possibly along pre-existing points or fault traces, a major period of speleogenesis apparently began during Tertiary regional uplift which induced subsurface piracy of Papoose Creek.

The vadose streams prodvced typical canyon-like cave passages. Through time, upper levels were abandoned and were decorated by a variety of speleothems.

The climate within the cave is severe with an average temperature of 2'C in the stream passages and about 4.5'C in the abandoned upper levels. The cave exhibits a mild seasonal chimney effect and also responds to short-term barometric shifts.

This severe environment seems to have limited the abundance of biota in the cave. However, a through biological assessment has yet to be carried out.