All objects, big or small, cast shadows and so do mountains.
However, one particular peak displays a peculiar behavior – it casts shadows not only on the ground, but also up in the clouds.
This photo of Mt Rainier was captured by Lisa Bishop. 
Discussion
Wow! That’s a first.
It's uncommon to catch Ranier without low cloud cover obscuring it.
Having a clear dawn with only cirrus clouds in the sky generally means it's winter and the sun is at it's southern most point.
(This phenomenon is most visable from a position north of Ranier)
I only caught the shadow a couple times in the time i was in the PNW.