The landscape of Brunswick, Maine, tells a story written in stone and ice over millions of years. The bedrock foundation consists primarily of granite and gneiss, ancient rocks formed deep within the Earth's crust. These metamorphic and igneous formations provide the geological backbone of the region.

Approximately 25,000 years ago, during the last glacial maximum, the Laurentide Ice Sheet covered all of New England, including the Brunswick area. This massive ice sheet, up to a mile thick in places, scoured the landscape, carving valleys and shaping the terrain. As the climate warmed, the ice sheet began its slow retreat, and by approximately 13,000 years ago, the region was ice-free.

The retreating glacier left behind a transformed landscape. Glacial meltwater carved deep river valleys, including the valley now occupied by the Androscoggin River. The river itself became a major feature of the region, flowing from the mountains of New Hampshire and western Maine toward the Atlantic Ocean.

One of the most significant geological features in Brunswick is Brunswick Falls, also known as Pejepscot Falls. These falls consist of granite and gneiss formations with three distinct tiers, created as the river cut through the resistant bedrock. The falls have been a focal point for human activity for thousands of years, serving as both a natural barrier and a source of power.

Meltwater from the retreating ice transported vast amounts of sand, creating a delta where the river met the sea. Wind later reshaped these deposits into the sand dunes and plains that distinctively mark the local topography.

Brunswick's ecological communities reflect the complex interplay between geology, climate, and biological processes. The forests are characterized by mixed-wood communities, combining both coniferous and deciduous species. Coniferous forests are dominated by Eastern white pine and Eastern hemlock, often found growing on the region's sandy soils.

Deciduous and mixed forests include Northern red oak, red maple, sugar maple, and paper birch. Wetland ecosystems are scattered throughout the area — marshes, swamps, and vernal pools — providing critical habitat for amphibians, waterfowl, and many plant species adapted to saturated soils.

Coastal ecosystems along the nearby shores of Casco Bay and the Androscoggin River estuary support salt marshes, tidal flats, and intertidal zones, providing habitat for marine and estuarine species and migratory birds.

The greater Brunswick area supports a rich diversity of wildlife. Mammal species include white-tailed deer, red foxes, raccoons, porcupines, and the re-established fisher. Moose and black bears occasionally pass through.

Bird populations are diverse: chickadees, nuthatches, and woodpeckers year-round, plus migratory raptors. The Merrymeeting Bay ecosystem supports a high density of bald eagles, often seen hunting alongside ospreys and red-tailed hawks. The Androscoggin and its tributaries host river herring (alewives), brook trout, smallmouth bass, and ancient species like the shortnose and Atlantic sturgeon.

Amphibians and reptiles — spring peepers, wood frogs, salamanders, garter snakes — depend on the area's vernal pools and forest habitats.

For thousands of years before European settlement, the Wabanaki people (People of the Dawnland) inhabited the lands that now include Brunswick and the greater Androscoggin River region. This area was the home of the Pejepscot band of the Abenaki. The name "Pejepscot," still used today, derives from the Abenaki language and is often translated as "long, rocky rapids."

The falls at Pejepscot were a critical economic engine — the natural barrier concentrated migrating fish, making it a prime location for harvesting salmon, shad, sturgeon, and alewives. The Pejepscot Portage was a well-worn trail connecting the Androscoggin to the salt water of Maquoit Bay, allowing the Wabanaki to bypass the long journey to Merrymeeting Bay.

The Wabanaki relationship with the land was based on principles of reciprocity and respect. They understood themselves as part of the natural world rather than separate from it. Today, the legacy of Wabanaki presence is increasingly recognized through the preservation of portage routes and continued stewardship efforts of the contemporary Wabanaki nations.

European settlement began in 1628 when Thomas Purchase set up a trading post near the falls. The 19th century brought massive industrial scale — Brunswick became a significant industrial center, dominated by the Cabot Manufacturing Company (now the Fort Andross building).

By the mid-20th century, the Androscoggin had become one of the most polluted rivers in the United States. The river's degradation was the primary inspiration for Maine Senator Edmund Muskie to author the Clean Water Act of 1972, which turned the tide and set the stage for the river's slow but steady recovery.

The Androscoggin River has undergone substantial recovery since the Clean Water Act. Fish populations are more diverse and abundant than in the mid-twentieth century. Ancient migratory species, including Atlantic and shortnose sturgeon, have reappeared in the lower river and in Merrymeeting Bay.

Land conservation began with the Brunswick Town Commons, set aside in 1719 — among the oldest town commons in the United States. Modern organizations have expanded this legacy: the Brunswick-Topsham Land Trust has conserved more than 3,300 acres of forests, wetlands, farmland, and riverfront. Working alongside partners like the Harpswell Heritage Land Trust and the Maine Coast Heritage Trust, these organizations help protect networks of land across the region.

Restoration efforts include removing obsolete dams to support fish migration, restoring coastal salt marshes for flood protection, and managing invasive species like the Hemlock Woolly Adelgid, Asiatic bittersweet, and glossy buckthorn.

Pejepscot History Center — Established in 1888, preserves and interprets the history of Brunswick, Topsham, and Harpswell. pejepscothistorical.org

Brunswick-Topsham Land Trust — A nationally accredited nonprofit maintaining over 3,000 acres of conserved land with trails and educational programs. btlt.org

Harpswell Heritage Land Trust — Protects coastal and inland properties in the Harpswell area. hhltmaine.org

Maine Coast Heritage Trust — Conserves and stewards Maine's coastal lands and islands, including properties in the Casco Bay region. mcht.org

A visit to Curtis Memorial Library can provide additional resources and information about the natural history of the greater Brunswick area.