Narragansett Bay is a bay and estuary on the north side of Rhode Island Sound. Covering 147 miles, the Bay forms New England's largest estuary, which functions as an expansive natural harbor, and includes a small archipelago. Small parts of it extend into Massachusetts.
Over 40 islands in the Bay
Of over 40 islands in the Bay, the three largest ones are Aquidneck, Conanicut, and Prudence Islands. Bodies of water that are part of Narragansett Bay include the Sakonnet River; Mount Hope Bay; and the southern, tidal part of the Taunton River. The Bay opens on Rhode Island Sound — Block Island lies less than 20 miles (32 km) southwest of its opening — and the Atlantic Ocean.
Narragansett Bay is a ria, a drowned river valley that remains open to the sea. It consists of a series of flooded river valleys formed of dropped crustal blocks in a horst and graben system that is slowly subsiding between a still-shifting fault system; however, the estuary system is vast compared to the present flow of the four small rivers that enter the Bay: in the northeast, the Taunton River and in the northwest, the Providence and Seekonk Rivers, along with the Pawtuxet River from the west.
The present shape of Narragansett Bay is instead the result of the most recent glaciation of New England, under the edges of the Laurentide ice sheet at the Last Glacial Maximum, about 18,000 B.P. Sea level was lowered so much that the continental shelf was exposed, under its weight of ice, and the glacier calved into the Atlantic at its foredge south of Block Island. Glaciers flowing through a geologically old sedimentary basin carved channels through the younger sediments and exposed much older bedrock. North-to-south cuts gouged by the ice can be seen clearly on the map: they form the West Passage that separates Conanicut Island from the western mainland and the East Passage that now separates Conanicut Island from Aquidneck Island.
As the ice stalled, then retreated, the region became ice-free by about 14,000 B.P. A complicated sequence of marine ingression and isostatic rebound flooded and emptied the landscape. A fresh water proglacial lake called by geologists Lake Narragansett formed about 15,500 B.P., impounded behind terminal moraines: the lake lasted about 500 years, leaving the powerful flow of a post-glacial river running down its north-south axis. Then salt water filled the valley, as rising sea levels permanently flooded the area.
First European visitors
The first visit by Europeans to the Bay was probably in the early 16th century. At the time, the area around the Bay was inhabited by two different and distinct groups of natives: the Narragansetts occupied the west side of the Bay and the Wampanoag occupied the land east to Cape Cod.
It is accepted by most historians that first contact by Europeans was made by Giovanni da Verrazzano, an Italian explorer who entered the Bay in his ship La Dauphine in 1524 after visiting New York Bay. Verrazzano called the Bay "Refugio" (the "Refuge"). The Bay has several entrances, however, and the exact route of his voyage and the location where he laid anchor is still a subject of dispute among historians, leading to a corresponding uncertainty over which tribe made contact with him. Verrazzano reported that he found clearings and open forests suitable for travel "even by a large army," a far cry from the impenetrable tangle that resulted when the English suppressed controlled burns in the seventeenth century.
In 1614, the Bay was explored and mapped by the Dutch navigator Adriaen Block, after whom nearby Block Island is named. The first recorded European settlement was in the 1630s. Roger Williams, a dissatisfied member of the Plymouth Colony, moved into the area around the year 1636. He made contact with the Narragansett sachem called Canonicus by the Europeans, and set up a trading post on the site of Providence. At the same time, the Dutch had established a trading post approximately 12 miles (20 km) to the southwest which was under the authority of New Amsterdam in New York Bay.
In 1643, Williams traveled to England and was granted a charter for the new colony of Rhode Island. He also wrote a dictionary of the Narragansett language, Keys to the Indian Language, which was published in England that same year.
Roger Williams and other early colonists named many of the islands in the Bay. To remember the names, colonial school children often recited the poem: "Patience, Prudence, Hope and Despair. And the little Hog over there."