The Great Wall

Another painting located in Arches National Park in Utah where there is this line of mesas and buttes called The Great Wall with a lot of them having these flat green areas on their sides where something (glaciers?) has worn away the sides to look like this. Can't see how it could be wind or water that could have done this...
There have been some fantastic towering cumulus clouds inland from where I live in Southern England recently and these gave me the idea for this picture. I decided to have an area in the distance in sunlight the rest was to be in shadow to emphasise the whiteness of the clouds. 
This is of course another in my The Great Sky series.
Oil on linen 30" x 20"
There is a step-by-step progress through this painting including the colours I used in previous posts on this blog.