range of granite hills, eastern Uruguay. It forms the eastern limit of the Negro River drainage basin and the watershed between it and that of the Mirim (Merín) Lagoon to the northeast at the Brazil-Uruguay border. The Grande Range extends about 220 miles (350 km) southward from the Brazilian border, almost to the Atlantic seaboard in the south, and rarely exceeds elevations of 600 feet (180 m), although it reaches 1,683 feet (513 m) at Mount Catedral, in the southeast. Its relief, though low, is sharp, angular gray rocks often protruding through the soil along the ridges. A westward extension, the Grande del Durazno Range, separates the drainage basins of the Negro (north) and Yi (south) rivers.