Trip leaders spend a great deal of time planning for their trips. Some trips are more challenging that others. If you are traveling on US Parkland or need access from private property, you will probably need to secure permits or gain permission. I like to do this task early on so I can reserve the best dates possible. When I plan my annual Lower Yough raft/kayak trip, I purchase the permits at the beginning of the new year for a trip in July - 6 months in advance. This is necessary since the Lower Yough is very popular indeed. Once you gain written permission, print a copy and store with your gear to avoid any misunderstandings on the day of the trip.