Customizable Ramp with Stones

I recently bought TerraTiles from RAINN Studios. They are a modular wargame terrain system. They come with 1" risers for the tiles so you can make hills and elevation for your games. The tiles include rivers and roads, which look a little odd going up elevation without some visual attachment. So I created this thing so I can make rapids for the rivers, and ramps for the roads.

Size and shape of the stones, as well as the size and aspect ratio of the base are customizable. Take note that Terra