KINTLA FORMATION.
These beds have the same bright red color as those of the Grinnell. However, because they are the youngest rocks of the Belt series they outcrop only on a few mountaintops, and inasmuch as these are mainly in the northwest part of the park, comparatively few people have noticed this formation. Visitors to Cameron Lake in Waterton Lakes National Park can see it in the red north wall of Mount Custer. The mountains around colorful Boulder Pass and Hole-in-the-Wall Basin are likewise composed of it.
Within the rocks of this formation there is a great abundance of small cubes believed to be casts of salt crystals which formed when the sediments were accumulating. Their presence indicates an arid climate and intensive evaporation of the sea, similar to the condition at Great Salt Lake today.