There's an issue with rivers in the current iteration of After the End which I can't figure out-- some of the rivers aren't navigable, but some are. Like, the Erie Canal and Mohawk River are can be sailed down, but the Hudson River can't, and I can't figure out why the former two river provinces work and the latter doesn't.
The revelevant bit in default.map for that specific example is as follows
And the map in that area is as follows
There's a portage between the Erie Canal and the Mohawk; even that works just fine, but I can't seem to carry on into the Hudson from the Mohawk.
Likewise the Mississippi River seems locked up in the same way, and I suspect the reasons for both the New York rivers and the Mississippi being screwy are related.
The revelevant bit in default.map for that specific example is as follows
Code:
sea_zones = { 3093 3177 }
ocean_region = {
sea_zones = { 1 } # Atlantic Ocean
}
# Define which indices in trees.bmp palette which should count as trees for automatic terrain assignment
tree = { 3 4 7 10 }
major_rivers = {
3107 3108 3109 # 3107 is the Hudson, 3108 the Mohawk, and 3109 the Erie Canal
}

There's a portage between the Erie Canal and the Mohawk; even that works just fine, but I can't seem to carry on into the Hudson from the Mohawk.
Likewise the Mississippi River seems locked up in the same way, and I suspect the reasons for both the New York rivers and the Mississippi being screwy are related.