When you are in the Main Menu, select (Continue) and then you select one by pressing (A) button.

Password	Effect
0HMQ83CYNX	Training Complete.
2WOW.5FWLV	Old Town Complete.
2WOWCR3YLV	Big Mountain Way Start.
4.6.2FZ8J9	Lazy "T" Ranch Complete.
4.PBWZ.J9	New Park City Complete.
KCHCMRYC3B	Petey's Gravel Pit Complete.