Ok it has taken a little time but I have finished the first butte, less some vegetation. Here are some WIP shots. The camera has dulled down the orangey colour a little but you get the idea.
First undercoated. In hindsight black was not a good choice and I shall be going for a more softer undercoat for future builds.

Next with the first brown coat.


As you can see I have mixed a little orange into the colour.

Whilst waiting for the next coat I took a shot with a 28mm Redskin to give you an idea of the size.

Then I added successive coats of orange mixed with yellow to build up the colours and make it softer.

And then finally with a light brushing of sandstone to tone it all down.

And from the other side.

Just need to add a little vegetation around the base and it is good to go. I plan to make another two variations and some slightly smaller rocky outcrops to use as scatter terrain. I'll post them up in due course but now am turning my attention to painting some more figures.