Narragansett Bay, arm of the Atlantic Ocean, 30 mi (48 km) long and from 3 to 12 mi (4.8–19 km) wide, deeply indenting the state of Rhode Island. Its many inlets provided harbors that were advantageous to colonial trade and later to resort development. At the head of the bay is Providence; at the SE corner of the northern bay portion is Newport. Conanicut Island and Prudence Island are also in Narragansett Bay, which is spanned by Newport Bridge (1969; 1,600 ft/488 m). The bridge links Newport with Jamestown.