Border River stands for its name - it separates Wilderness from the Eastern regions thus making the crossing of the river rather useless. Unless you're trying to flee from angry villagers or trying to bypass River Dea.
This river flows from Strongholm Marshes through Bokrug Lake and finally into River Dea. Border River's tributary is River Saisuku flowing from Lake Chuckles.
The settlement Divine Nation was on the shore of the river as it entered Lake Bokrug.