You'll have no problem as long as you have the following on your person:

1. Valid hunting liscens from your home state w/ signed Federal Duck stamp affixed
2. Valid drivers liscens
3. Valid hunting liscens from the state in which you are now hunting
4. HERES THE KICKER: you have to check the regs in the area/state in which you plan to hunt becuase you may need the following:
1. State duck stamp
2. County duck stamp
3. WMA duck stamp

Other than that you're golden. Hope it helps