Sculpting Mountains from foam panels (Forced Perspective distant range for O-scale)

I used a tacky glue (almost like rubber cement) to hold my "grass" fibers in place. Since it always stays tacky, I decided to sift the finest dirt over the grass and allow it to fall between the fibers and stick to the glue, then I simply vacuumed up the excess dirt. To make sure the dirt melded into place, I gave it a mist of water and fan dried it from a distance. (HO-scale)