Didn't have to wait very long for the next shuttle to arrive.
We had to ask the information center for the appropriate shuttle line up as there are quite a few busses and shuttles leaving from the same place. We were looking for a Viator sign but there were none, finally by asking a few people we managed to get onboard the right shuttle. The shuttle service was good although we were stuck in traffic on the way back due to a previous truck accident on the highway in which we were not involved, but the driver kept us well informed of the situation and updates.
The glacier is impressive as is the crowded conditions at the glacial visitors center. The shuttle driver, Fred, was great with his narrative. Fun jokes for the kids, and he spotted bears and bald eagles for passengers.