I agree with Seth - I want to increase my sun settings to make that area brighter but unfortunately it makes the sky look very bright. Plus it exposes my lacklustre ability to make convincing rock formations.
I have a few ideas though so I'll try them as soon as I have time. I'll try experimenting with Perlin Ridges for rock structures and add a few grass clumps or weeds at the front to increase realism. Maybe then I can increase the sun's power but find a way of keeping the sky fairly dim.
In the meantime, here is the image rendered with much higher settings. Rendering the tree population in medium quality instead of low certainly made the trees appear more densely packed.
My ultimate hope is to have godrays streaking in from the left between the furthest visible mountain and the hill closer to the camera, but not between the closest two hills.