So we get these 5 Riverwalk cards, one for each player, they are pictured on page 9 of the rulebook.
I get the right hand side, it just tells me what territory each riverwalk ability allows you to move into. The left hand side however is a map with faction icons on it. At first I thought it showed who could move into which ones home territory as it claims. But then I noticed that this is not true.
For example the mountain in the Crimean Khanate territory has only the Nordic and Saxony faction symbols even though Polania can move into mountains as well.