Tags: Mountain Range.
The Chiwaukum Mountains are a north-south mountain range in central Washington USA. They stretch from Snowgrass Mountain at 47°41′N 120°56′W to 47°45′N 120°54′W.The mountains are made of schist part of the Nason terrane. The original rock in the Nason terrane was laid down 210 Myr ago. The terrane then smashed into the western coastline of the continent and the Mount Stuart batholith intruded into it in the late Cretaceous.
