Airport Shuttle Service (Van):
Grand Rapids to South Haven: Friday at 1pm, arriving by 2:30pm at the Lodge.
South Haven to Grand Rapids: Sunday at 5pm, arriving at the airport by 6:30pm.
If you need to arrive the day before or would like to stay a day after I recommend the Ramada Inn. They offer 24-hour free shuttle service to the airport and you can travel back to the airport for the retreat shuttle.