The national park employees cannot seem to get it together to take reservations for this tour. All they have to do is take down x number of names and then take x number of people on the tour. The office seemed to be always jammed with people whose reservations had been lost. They screwed ours up two nights in a row, and we met two women who had flown in for the tour from San Jose. You guessed it, they lost their reservations too. Also you need to bring your passports with you and show it to them, which seems a little over the top. So my suggestions are to take a copy of your passport and let them deal with a copy and keep your passport on you. Second get the name of the person who accepted your reservation, and or bring your reservation in writing, or you may make a very long trip for nothing.