Possibly in the forest
there's no moss rock in heartgold/soulsilver. To get it you need to trade from a different game. Sorry!
There is it is in ilex forest
the moss rock is in Eterna forest
no
Digletts Cave.
You use rock smash and can sometimes find fossils.
you cant since the moss rock u need to evolve it is only peal diamond and platinum
After beating blue, the 16th gym leader
You need to train an Eevee at Moss Rock in Eterna Forest.
There is no mossy rock in HeartGold. There is not one in SoulSilver, either. A mossy rock is only found in Pokemon Diamond and Pearl. You must trade for a Leafeon to get one in Pokemon HeartGold.
Moss Rock does not exist in Leafgreen as it was introduced in Diamond, Pearl, and Platinum.
They are in the Safari Zone