I've used this road just three times but one spot always gets my attention.

somewhere along the expressway to the right, there is this large fraction of the hill which seems to be cut open. that part of the hill is coloured red/whitish from the distance. it lacks vegetation and it looks like a cut by erosion or maybe its man made.
I could not get a picture of it but since NLs are scattered across the country , I believe someone would be able to help answer my question here.
is that a natural phenomenon or its man made ?