The Pocomoke River drains 679 square miles of the Atlantic coastal plain; the watershed is ~20% wetlands and ~80% uplands.  The Pocomoke is characterized as a blackwater river, draining forests, agricultural and poultry operations.  From the head of tide at Snow Hill, MD, the narrow river channel meanders seaward 35 miles to Shelltown, where it opens rapidly to the broad, shallow Pocomoke Sound.  The estuarine portion of the Pocomoke River begins near Pocomoke City, 15 miles from its mouth.