Above is a long ridge representing the western rise where the two ambushing cells are positioned. I built it up from three layers of polystyrene on a plywood base, picked into a rough ridge, then coated with pre-tinted all-purpose filler. I added stones as boulders for a bit of cover, & then a coat of sand to the upward surfaces. To brake-up the monotony of what will largely be ochre/tan terrain, I went with a pinkish soapstone effect for the rock. I've modeled the far end of this ridge in cross-section so that it can be placed up against a board edge.
I've also finished a pair of scrubby, rock-strewn areas for the west side of the board (below). These are simply plywood bases with a bit of filler-texture & stones. The scrub is a mixture of lichen & specks of flock. I kept the soapstone theme for these rocks, to match the ridge:
Finally, below is a closeup, featuring the first 15mm figure I ever painted, a PLO fighter from Peter Pig: