Long ago, before there were roads anywhere north of Tethyr, the Dessarin was known as the Road to the North. The river reaches up past Waterdeep to the Evermoors, and into the eastern end of the Spine of the World.
When humankind first explored the North, they chose the surprisingly fertile Dessarin delta for their first settlements. To this date, more humans live in the long, broad valley of the Dessarin than in any other part of the Savage Frontier. The farms and ranches of the delta feed the remote mining settlements of the North, and fall prey to the orc hordes that sweep down the Dessarin every decade or so.
This great river carves the rough hills of the central North into a broad, gentle valley. It is the principle route for trade and commerce in the region, linking Waterdeep near its mouth with Yartar and Silverymoon hundreds of miles upstream.
Minstrels sometimes describe the Dessarin as a sword thrusting up into the heart of the North. In fact, the river itself was once known as the Sword. This is important knowledge to those puzzling out Netherese and other ancient writings, trying to locate important sites or priceless treasure.