Q-Deck,
I use plaster impregnated bandage. You can get it from hobby shops reasonably cheaply. It's pretty much the same stuff they wrap your broken leg up in, but don't get it from the chemist shop. It's 2 - 5 times the price.
Dip that in water and lay it over the top of the mountain. Massage it a bit, to even it out etc.
I then mix a teaspoon or so of cheap artist paint (earth colours) $1 a tube or so, from the hobby arts shop, with a bowl of reasonably sloppy (porridge consistency) of plater of paris and paint this on (1/8 inch thick) after the plaster bandage has pretty much set. Lump it up, and sculpt with a knife to represent cracked rocks and outcrops etc. Then get some other "earthy" coloured paints, and just a smidge in a bowl of water, (really thinned down) and then dribble this over the painted on plaster (just before it really dries out), and let it run down the sides, to simulate the water runoff and weathering of the ground.
VOILA!! One rocky mountain!!
Cuppla hours for all that should do it.
Let it dry completely, then use white wood glue, and paint this all over, (except where you want exposed rock) and sprinkle on some ground cover, then give a light spray with water.
You can make your own ground cover. Just put some dead leaves etc in the blender and push the button!!!

or colour some sawdust and let it dry out.
As for snow? ummmm..... I've never had to do snow.
Any suggestions guys, for a "snow sprinkle" cover? Maybe use that "Santa Snow" stuff out of a spray can that everyone uses at Christmas time????
Good luck.
