Oak's letter could only be obtained via Wi-Fi during the event. However, the event is now done. But if you already obtained it during the event, then simply go to the Pokemart and talk to the delivery man, he'll give you Oak's Letter.
River Oaks Center was created in 1966.
u need oaks letter...................
you need oaks letter and you need to go to a Nintendo event to get the letter
The address of the Fair Oaks History Center And Museum is: 7997 California Ave, Fair Oaks, CA 95628
Sherman Oaks Center for Enriched Studies was created in 1981.
you use a action replay and use it to get oaks letter
you can not find it at any of the poke centers or anywhere else but through action replay or Events.When you have the action replay code you can get it at any pokemarts from a man in green
The web address of the Hidden Oaks Nature Center is: http://www.fairfaxcounty.gov
get the oaks letter cheat on the action replay and talk to the guy in the pokemart
The phone number of the Hidden Oaks Nature Center is: 703-941-1065.
The web address of the Irons Oaks Environmental Center is: http://www.ironsoaks.com/
You get oaks letter from a special event that is on the internet or wifi. you get it from any poke-mart in sinnoh