When you select a put-in location, the take-out dropdown only shows locations within that same area. If your trip ends in a different area, your take-out won't appear in the list — and you'll need to check Other areas to find it.
In the Guide App
In the Where did you put the boat in? field, select your put-in location (e.g., Turah).
In the Where did you take the boat out? field, check the Other areas box.
Select the area where your trip ended (e.g., Lower Clark Fork River).
Choose your take-out location (e.g., Sha-Ron).
The same steps apply when completing a guide report on the web.