Do you mean Mistralton Cave? There are Joltik, Ferroseed, Klink, and the occasional Drilbur and Tyamno.
You get it at Mistralton Cave
mistralton cave
mistralton cave
mistralton cave
Find one in the mistralton cave.
In Mistralton Cave
In a house in Mistralton city.
He is in Mistralton City in the house next to the pokemon center
You have to surf on the river at route 6.
You find Cobalion on Mistralton Cave.
Mistralton PokeMart - 50,000 Pokemoneys
Mistralton city. It's to the right of the Pokemon center