Several hundred feet of limy beds which weather yellow-brown lie on top
of the Siyeh. Although named for outcrops on the cliff above Shepard
Glacier (south of Stoney Indian Pass and near the site of the old
Fifty-Mountain tent camp) the formation is exposed on the summit of
Swiftcurrent Mountain at the head of Swiftcurrent Valley, on Reynolds
and Clements Mountains near Logan Pass, and on Citadel and Almost-a-Dog,
visible from Going-to-the-Sun Highway in St. Mary Valley. The formation
is replete with mud cracks and ripple marks. Some rock surfaces exhibit
two and three sets of the latter.