Block Island
Block Island is a glacial terminal moraine island situated in Block Island Sound of the Atlantic Ocean, approximately 12 miles southeast of mainland Rhode Island, encompassing the entirety of the town of New Shoreham, Rhode Island's smallest and least populous municipality by land area and permanent residents.[1] The island spans about 7 miles in length and 3 miles in width, covering roughly 7,000 acres of land characterized by rolling hills, freshwater ponds, and extensive beaches backed by steep bluffs.[1] Its year-round population hovers around 1,400, though it surges to over 10,000 in summer due to tourism drawn to its natural landscapes and coastal scenery.[2] Originally inhabited by the Manissean band of Narragansett Indians, who named it Manisses meaning "island of the little god" and maintained a population estimated at 1,200 to 1,500 prior to European contact, Block Island was first charted by Dutch explorer Adriaen Block in 1614, after whom it is named.[3] English settlement commenced in 1661 under a charter from the Rhode Island colony, leading to rapid displacement of the indigenous population, which dwindled to near extinction by the late 18th century through disease, warfare, and land loss.[4] The island's economy historically relied on farming, fishing, and sheep husbandry, evolving into a resort destination by the late 19th century with the construction of hotels and steamship services.[3] Block Island features two prominent lighthouses—the Southeast Lighthouse, a 52-foot brick tower erected in 1875 atop Mohegan Bluffs with a distinctive green flash, and the North Light, a granite structure built in 1867 at Sandy Point—both essential for maritime navigation in the hazardous waters of Block Island Sound.[5] Over 40% of the island is preserved as conservation land, including the Block Island National Wildlife Refuge, supporting diverse birdlife and rare plant species amid its dunes and wetlands.[3] Access is primarily via ferry from Point Judith, Rhode Island, or limited air service, with no bridge connection, preserving its isolation and appeal as a haven for ecotourism, cycling, and offshore wind energy development, including the nearby Block Island Wind Farm operational since 2016.[1]
Geography
Location and Topography
Block Island constitutes the entirety of the town of New Shoreham in Washington County, Rhode Island, situated approximately 12 miles south of the mainland in Block Island Sound at coordinates 41°09′42″N 71°35′04″W.[6][7] The island measures roughly 7 miles in length and 3 miles in width, covering a land area of 9.734 square miles (25.21 km²).[8][1] The topography features undulating hills with a maximum elevation of 206 feet (63 m) at Beacon Hill in the island's southwest.[9] Inland areas exhibit gentle rolling terrain interspersed with over 300 freshwater ponds, while the coastline encompasses 17 miles of beaches, including steep bluffs rising up to 200 feet along the southern shore.[10][11] The northern and eastern coasts present more gradual slopes descending to sandy shores.[12] Positioned as the easternmost point of Rhode Island's territory, Block Island lies about 14 miles east of Long Island's Montauk Point across open waters of Block Island Sound, with no intervening landmasses.[10] This isolation contributes to its physical distinctiveness within the Outer Lands archipelago, marked by low average elevations around 16 feet above sea level.[13]Geology and Hydrology
Block Island formed as a depositional feature of the terminal moraine associated with the late Wisconsinan glaciation, with glacial advances depositing heterogeneous tills and outwash materials approximately 18,000 to 20,000 years ago.[14] [15] Superimposed drift sheets on the island indicate fluctuations in the ice margin during this period, contributing to its varied topography of rolling hills, clay bluffs, and sandy lowlands.[16] The Mohegan Bluffs exemplify these glacial processes, rising to about 150 feet in elevation and composed of compacted clay-rich till exposed by post-glacial erosion.[17] Soils on Block Island are predominantly permeable sands and loamy sands derived from glacial till and outwash, overlaying denser basal tills in some areas.[17] [18] Glacial erratics, boulders transported and deposited by the ice sheet, are scattered across the landscape, with concentrations armoring beaches and pond shores.[19] These features shape the island's drainage patterns, creating numerous closed depressions that host over 20 significant freshwater ponds, including Sachem Pond near the southern coast.[17] Hydrologically, Block Island has no perennial rivers, depending on these ponds and a thin unconfined aquifer of glacial sands for freshwater.[17] The aquifer floats atop denser saltwater, rendering it susceptible to intrusion in low-lying coastal zones due to the porous sediment structure and proximity to the ocean.[17] [20] Oceanic processes continue to influence the island's margins, eroding bluffs and reshaping depositional sands, while maintaining the hydrological reliance on precipitation-recharged ponds and groundwater.[14]