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Harpswell’s Island Heritage

Steve Ingram
October 7, 2022


Harpswell Township is home to almost half of Casco Bay’s more than 200 islands, listing 98 islands within its borders. Four of these are the heavily-populated Great Island (formerly Sebascodegan Island), Dingley Island, Orr’s Island, and Bailey Island. That leaves 94 “outer” islands, accessible only by water or air. The exact count can be disputed since there is no common agreement on the distinction between islands, ledges, rocks, or other land masses visible only at some tides. This article will focus on our 94 named outer islands.

These islands contribute a significant proportion of Harpswell’s total shoreline of 216 miles and a less, but still significant, percentage of its total acreage. They have played an important role in Harpswell’s history and continue today to have a positive impact on Harpswell’s economy. The islands’ heritage is a testimony to the resourcefulness required for survival of both the land and its people; a heritage that is a source of pride for all who call Harpswell home and that portends the character of our 21st century Harpswell.

Using the Harpswell Heritage Land Trust’s motto: Nature, Community, Forever as an organizing principle, this article discusses the islands’ NATURE — its geology, flora and fauna; the islands’ COMMUNITY — the history of human presence, inhabitants, and ownership; and the islands’ FUTURE — environmental forces, human impact, preservation initiatives, and civic responsibility.


Geology: The Harpswell islands’ geologic history can be traced back 500 million years. Radiocarbon dating of the oldest rocks on the islands in Casco Bay date them 470 million years old. At that time layers of sediment were deposited on an ocean floor covering what is now Casco Bay. These sediments were metamorphosed into rock by pressure from natural forces. It is hard for us to imagine geologic time measured in millions of years, but over the millions of years since there were periods of relative calm punctured by violent upheavals — earthquakes, volcanoes, and land mass collisions. The horizontal beds of sedimentary rocks were thrusted up to near vertical, twisted, folded, and reshaped in every possible way. Such rocks, now exposed as a Harpswell island, have been subjected to the erosive action of coastal storms, wind, ice, and tides, exposing the fractures between layers and sharpening the rock edges. Try walking barefoot on the ledges of Little Whaleboat, for example, or check the southeast sides of the islands where great vertical slabs of rock layers calve off the cliffs.

The earth’s land masses, split by volcanic or earthquake activity, collided and reformed in different configurations, only to be torn apart again. Just prior to the current continent configuration there was only one landmass on the earth, Pangea, and it covered what is now Casco Bay. A major fault line in what we call the Atlantic Ocean split North and South America from Europe and Africa. Researchers have found rocks with the same component makeup on our New England east coast and on the west coast of Italy, offering evidence that we were once close neighbors, if not the same land mass.

But don’t try to find fossilized ancient pasta on Harpswell islands — too much has happened since then. Multiple periods of glaciation and melting have occurred, the latest period of glaciation at around 20,000 years ago. At that time Casco Bay and our island area were under a glacier more than a mile thick. Geologists can track the movement of that glacier generally southeast in a path over the Casco Bay region toward Long Island, NY. Evidence of that movement can be found on Harpswell islands where vertically uplifted outcrops have been scoured by glacial movement leaving glacial scars in that southeasterly direction. Eagle Island invites visitors to see such scars when they tour the island. You can look for them at the height of land on other islands when an outcrop is exposed, usually along a summit ridge. Don’t be disappointed if you don’t find any because most have been eroded smooth, but what excitement when your search is successful!

As the latest glacier receded, the Portland area, including Harpswell, was 200 feet below the ocean surface. Over the centuries as the glaciers receded, the race was on between the rising ocean levels caused by the melting ice and the rebounding action of the land masses as the weight of the ice diminished. Our islands, formed eons earlier by continental collisions to be foothills to the mountains to our west, won their race and broke the ocean surface. The resiliency of their bedrock formations met the challenges of weather, wind and tides to stand today as a proud heritage of the Harpswell citizenry.

Flora: The geologic action noted above resulted in many Harpswell islands following a northwest-southeast axis, similar to Harpswell’s mainland peninsulas. This orientation gives them a similar topography. A central ridge of uplifted schist runs parallel along this axis. Sloping northwesterly down from the ridge top are increasing depths of glacial till ancestral soils, in turn covered in increasing depths by thousands of years of organic decayed matter, making a rich topsoil, down to water’s edge. In the southeasterly direction, the direction of glacial movement, you often find steep cliffs where the glacier plucked the vertical layers of uplifted schist off the rock in great slabs. That is generally the ‘deep water’ side of the island, as opposed to the beachy side on the northwest. You often find visitors enjoying the beaches on the northwestern tips of Upper Flag and Little Birch, for example.

This diversity of topography encourages the diversity of vegetation found on Harpswell islands. Close to the ridge tops you will generally find northern hardwood trees with the advantage that they lose their leaves before the damaging winter winds. Below that, shallow-rooted deciduous and evergreens, birch, beech, and balsam fir can thrive. Further down, shrubs and berry plants nurtured by the rich topsoil can make hiking difficult but gastronomically rewarding. Grasses can generally be found on relatively level island grounds.

The canopy provided by this diversity of tree/shrub growth discourages some floral growth while it benefits others. Casco Bay is a moat around our islands, which denies the spread of seeds easily transported across the mainland. Nevertheless, a wide diversity of plant life is found on the islands due to wind transport, bird and mammal evacuations, and human impact. Recent floristic surveys of Maine islands and of Eagle Island in particular have identified over 55 floral species. You can even find some rare plant species, sometimes in abundance, on the islands. Wild leek, a form of wild onion (Allium Tricoccum) is a popular find on Eagle Island.

No individual Harpswell island is an isolated ecosystem. They all share a common but diverse island ecosystem. Unfortunately, this ecosystem is not immune from invasive species. Once a non-native species gets a foothold on an island, it is tough to dislodge and eliminate. Stewardship of our island ecology is a worthy endeavor!

Fauna: With the diverse topography of each Harpswell island supporting diverse vegetation, it only follows that the various vegetation types will be home and diet for a diversity of birds and mammals. Visitors to the islands will first encounter sea birds. Gulls and ospreys announce your presence well before your landing and register their objection to your intrusion in increasing volume as you walk ashore. Mostly invisible to you, but keeping a steely eye on your movements, are an occasional owl and Great Blue heron, who have left their wading hunts to wait out your visit in tree roosts. Common Eider families will lead their young from the shore to the water and paddle away from perceived danger. You can easily distinguish the Herring Gull from the Great Black-backed Gull as the name self identifies. With luck you may encounter Bald Eagles, or at least know they are around, from the disturbance of the other birds that telegraph any presence of that predator sea bird. Common songbirds found on the islands can include robins, warblers, sparrows, and finches. Any island visit is an adventure for a bird watcher, serious or amateur.

Ducks and gulls nest in the shrub areas, the denser the better, for protection and invisibility. Ospreys and eagles have perfected stick architecture in the tops of the hardwoods or suitable spruce trees. Nesting season goes from early spring to mid-July and the State of Maine asks that visitors go no further inland than the beaches on their islands until the end of nesting season. After mid-July, if you are lucky enough to get a glimpse of young Herring Gulls feeding, notice the returning parent with food in its crop. The chicks look for the reddish spot under the parent’s bill, peck at it, and that releases the stored food from the parent. You may also witness nature at its most vicious when young gull or duck chicks get taken by a Great Black-backed gull and eaten alive. Human incursions can often frighten a nest of chicks to scatter, decreasing their survival rate. Understanding this natural occurrence should be reason enough for all to honor the July 15th prohibition.

Mammals and reptiles are less prevalent on the islands but can still make their presence known. Mink, muskrat, and raccoons are swimmers and feed on the eggs of nesting gulls and ducks. Deer have been seen on Eagle Island and other islands grazing on the virtually untouched grasses. Visitors on Eagle Island watched as the deer swam from the island to Upper Flag Island and from there to Basin Point with only a small deer head visible above the water. Mice, voles, and snakes can startle a visitor and add to the wonder of how they got there. Historical records reveal that Harpswell farmers brought domestic sheep to the islands to keep them safe from land-based predators. Perhaps, such varmints found transport to the islands as the sheep were relocated. Similar extensions of mainland operations to the islands brought non-native species. For example, Adm. Robert E. Peary kept his sled dogs, dogs that had made his discovery of the North Pole possible, on Upper Flag Island after he returned in 1910. Transporting dogs, food and caretakers among the mainland, Eagle Island and Upper Flag Island provided opportunities for critters from “away” to take up residence; they are now part of the island fauna.


The one mammal species that has had the greatest impact on Harpswell’s outer island heritage is the human species. Our area’s indigenous inhabitants were “islanders” from the earliest recorded times. Prior to the arrival of domesticated pack animals, travel across water in canoes was a preferred method of transportation. Middens researched on Casco Bay islands suggest indigenous populations used island shorelines similarly to mainland shorelines for their easy access to fishing and shellfish harvesting, perhaps even becoming seasonal residents on the islands in the summer months; practices copied by early European settlers.

Harpswell’s first recorded non-native full-time resident on an outer island was Richard Potts, who lived on Haskell Island, then known as Damariscove Island, around 1670. Harpswell historian Dave Hackett says, although his students may think him old enough, he can’t personally vouch for the accuracy of such early accounts. But his research, supporting his engaging storytelling, makes a visit with him a fascinating outing. Stories passed down from generation to generation suggest that there were periods of sudden migrations from mainland to the islands and from the islands back to the mainland. For example, during the King Philip War and its tribal uprisings throughout New England, residents of Harpswell Neck exited on mass to Jewell Island for protection from possible raids. During the French and Indian War, tribes were encouraged by the French to raid such English settlements on the islands, forcing settlers to return to the mainland to benefit from British protection. Historic accounts record that during the California gold rush of 1849 most of the males on Birch Island left the island to join the rush west. Unfortunately for them, more gold has been found here on Cedar Ledge than they brought back from California. Although there is always hope and excitement that any trip to an island will offer the chance to uncover a lost pirate treasure, Cedar Ledge is the only Harpswell outer island that can claim such success.

Most of our more than 90 outer islands more recently have been, and currently are, vacation destinations for single families or small groups of families. Just two islands, Little Yarmouth Island and Long Island, have residents who list their island as their permanent residence. Only a small percentage of the islands have permanent houses and there has been very little recent construction on any of them. Eagle Island, Admiral Robert E. Peary’s summer home, now a Maine State Historic Site and a National Historic Landmark, is an exception. In the early 1900s he built his house and a caretaker’s cottage. A few years later his son added a workshop and in 2017, as a State Park, a Welcome Center was added. The caretaker’s cottage was the year-round residence of successive caretakers and their families. Harpswell’s “very senior” citizens tell of the Marden caretakers’ 10-year-old son rowing from Eagle Island to South Harpswell each day to attend school!

Earlier, the only Harpswell outer island that hosted what we might recognize as a year-round community was Whaleboat Island and they had their own schoolhouse for a short period. Buildings from that community, and at least in one case the entire Blake house, have been moved from Whaleboat to Harpswell Neck, the house to continue as home to Blake descendants. How Harpswell forefathers of that era could meet the challenges of such transport without today’s heavy equipment adds a sense of wonder to our heritage.

Families who are seasonal residents on an island naturally form neighborhood communities to address common challenges and enjoy casual celebrations. Recently some island communities have organized and been formally recognized as Associations or LLC’s. There are 11 such chartered organizations serving nine outer Harpswell islands today. Whether formalized or not, island communities, to face changing circumstances, have banded together for mutual benefit: from the need for security during the birth of America, to the service as observers during the World Wars, to the need today to meet the challenges of global warming on an island environment. Adaptation to change for mutual benefit is characteristic of Harpswell’s heritage and a basis for its resilience.

Prior to 1775, ownership of Harpswell’s outer islands was conferred only by King George of England. Today, ownership is deeded by the Town of Harpswell to be recorded on its tax rolls. There are 240 individual or family owners of the more than 90 Harpswell outer islands. Local, state, and federal governments own 27 islands outright and portions of three others. Conservation groups own five islands and portions of five others. (Harpswell Heritage Land Trust is the sole owner of Crow Island and Doughty Island and owns parcels of Birch, White, and Little Yarmouth Islands). Island associations own six islands with partial interest in three others. The remaining two thirds of the islands are owned by individuals and families as diverse as our local and east coast population.

It should be noted, here, that no Harpswell outer island has yet to declare “independence” from Harpswell!


The Harpswell islands are subject, of course, to the same global forces that will affect us all. But those forces will be nuanced by the islands’ oceanic platform. Climate change, energy dependence, and population densities are and will be global problems, but will have unique impacts on our island environment.

Climate change, with higher temperatures causing the melting of glaciers, will raise sea levels. For our islands this will have significant, and in some cases existential, impact. Ram Island, a small island just west of Potts Point, has decreased in size by 50 percent in the last 20 years. (So much so that some, watching the erosion year after year, now call it “Disappearing Island”). Other islands will cease to be islands, to be reclassified as ledges or rocks on future nautical maps. All islands will see erosion of their shorelines.

In our search for alternative energy sources, our islands can support the construction and maintenance of wind turbines and, perhaps, more permanent locations for the technology equipment critical to the energy transmission. Tidal generation may turn the ocean itself into an energy source.

Mainland population densities will encourage more people to consider an island as their permanent residence. We have two centuries of history of such migrations in Harpswell’s own Great Island, Orr’s Island, Bailey Island, and Dingley Island. We have 90 islands still available.

The preservation of our current island environments is the mission of several local conservation groups: Harpswell Heritage Land Trust, The Nature Conservancy, and Maine Coast Heritage Trust to name just a few. These groups, through the purchase of available tracts of land and the negotiation of easements of other tracts, protect them from further negative human impacts. But they cannot protect them from the forces of global change that Mother Nature has in store for us.


What can we learn from Harpswell’s outer island heritage? From its geologic and natural history, we learn that nature is a study of adaptations to change: island topography is the earth’s adaptation to natural forces; island flora adapts to changes in island topography; fauna adapts to changes in the island vegetation; the result: a resilient ecosystem. Likewise, Harpswell’s island citizenry adapted to changes in the social order over time: mobility in the face of impending danger; establishing family roots in specific locations in times of stability; but always forming communities for the common good; the result: the resilience of a civil humanity. We find evidence that this Harpswell heritage begets our local character. Our present day Harpswell community is characterized by a respect for the natural environment that requires behavioral adaptations, and by a willingness to meet civic challenges for mutual benefit-contributing to a civil society.

What does Harpswell’s island heritage offer us? It offers opportunity: the opportunity for full-time residency to mitigate, at least to some degree, the mainland population density; the opportunity for seasonal residents to imagine, realize, and practice new forms of civil neighborhoods for mutual benefit; the opportunity to walk through natural environments, relatively free of human impact; and, the opportunity to sit on a secluded beach, at one with the island at least for a short time, to see what the island sees: a lobsterman, finding livelihood where others seek respite; a kayak paddler, knowing satisfaction from progress through personal endeavor; a sailor, harnessing natural forces for momentum; the speedboater, always in competition to get there the fastest; or the yachtsman. The island sees all without judgement.

What can we offer, as thanks, to Harpswell’s outer islands? Preservation of all these opportunities! How lucky we are!