Drop-ins: Drop-ins welcome as long as there is room. There is a added $2.00 to the cost of any event if you are not preregistered. Payment is due at time of event. No Exceptions! Refunds:: Registrants wishing to withdraw their registration must do so no later than 5 business days prior to the scheduled start of the activity. You will be given a refund minus a $5.00 processing fee. NO refunds will be given if withdrawal is made less than 5 business days before scheduled start date. No refunds can be given for trips or tours after the registration deadline. Canceled classes: NPS reserves the right to cancel any event, class or program. NPS will make efforts to contact registrant 48 hours before the scheduled start of the activity. Complete refund will be given if cancellation occurs.