On the commercial side things are a bit different. Due to NPS concession management policy at the GCNP, river concessionaires are not allowed to book river trips more than two years in advance. Depending upon the time of year, one can reserve space on a commercial trip anywhere from immediately up to two years out to get the dates one desires. Of course, in order to reserve the dates one desires, it is usually necessary to make reservations at least 6 months in advance, particularly for popular dates during the Primary Use Season. However, cancellations are frequently available.
Cancellations are available for both the commercial and non-commercial user.
The commercial user can frequently pick up a commercial seat in less than two weeks. There is a telephone call-in procedure for people on the waiting list that works something like this. On Friday's, available cancellations are posted on a call-in number. On the following Monday, applicants on the waiting list with wait list numbers from 0 through 1499 may call in. On the Tuesday following, wait list numbers from 1500 to 2999 may call in.