Near bills house but you need to solve the power plant crisis first.
misty will be a gym leader in HeartGold and SoulSilver
route 25
After you defeat Misty, You can go catch suicune by Bill`s house.
Misty is at the Cerulean Cape. It's close to Cerulean City.
Misty has a 49 Golduck 49 Quasire 52 lapras and 54 starmie
She's at the end of route 25
top of rout rout 25 =]
misty
Route 25, near Bills house.
at the end of the cerulean cape (route 25)
You can go and challenge other Gym Leaders in the Kanto region, such as Brock.
its in 1 of the major caves i know you go straight from the enterance maybe cerulean in kanto where misty is