“…In the Maiden Peak spur, the Paleoproterozoic-Mesoproterozoic contact ("fault D" of M 'Gonigle, 1993'Gonigle, , 1994 is shown as part of the Medicine Lodge thrust fault (Ruppel, 1978), but this contact is reinterpreted as an unconformity (Tysdal and others, 2005). The Medicine Lodge thrust fault was also shown in the Lemhi Range and northern Beaverhead Mountains by Ruppel (1978) and Ruppel and Lopez (1984), but more recent mapping reveals that a thrust fault of this type does not exist in those areas either (Tysdal, 2002;Tysdal and others, 2005, respectively). Thus, a youngeron-older Medicine Lodge thrust fault has not been substantiated in any of the areas where it was originally depicted, including in the central Beaverhead Mountains.…”