Nature

 
Acadia National Park preserves approximately 50,000 acres along the mid-section of the Maine coast, containing the tallest mountains on the eastern seaboard, an iconic rocky Maine coastline, and subalpine rocky summits. The park’s mountains, lakes, streams, wetlands, forests, meadows, and coastlines contribute to the diversity of plants and animals found here. Acadia is within the transition zone between southern and northern forests, and as a result, hosts plant species and communities currently at the edge of their geographic range. The park’s location along the Atlantic flyway makes it an important resting and feeding place for migrating birds and bats.

During your visit, you join a legacy of centuries of interconnectedness between people and this landscape. For more than 100 years, a tradition of scientific investigation has joined a millenium of traditional ecological knowledge to form the bedrock of our understanding of Acadia's natural world. Help protect Acadia's natural wonders by following all Leave No Trace principles during your visit and reducing your carbon footprint as you explore.
 

Animals: A Place Called Home

Animals call Acadia 'home.' Their lives are inevitably wrapped up in ours as we move through the places they eat, sleep, and raise their young. Animals inhabit all of Acadia, from the smallest microorganism to the falcons and eagles that fly above the park's mountain peaks, and in every ecosystem in between. With a keen eye you can always be watching wildlife from a safe distance during your visit to Acadia. Simple acts like using long lenses when birdwatching can go a long way to keeping animals safe. Learn more about their remarkable lives and how you can protect Acadia's animals.
 
Three barred owls sitting on a tree branch
Acadia is home to a diversity of wildlife, from microorganisms living in tidepools to larger animals on land and in water.
 

Plants: The Green Kingdom

There are over 1,000 different types of plants in Acadia. As generations of humans worked these woodlands and waters and waterfronts, plants formed the foundation of their survival. On land, low-to-the-ground plants such as mosses, grasses, ferns, and lie beneath larger plants such as trees and shrubs. Joining these plants on the ground are lichens and mushrooms which are not true plants, but organisms that are unique in the natural world. In tidepools, saltmarshes, and on the coast, marine algae, seaweed, and other saltwater plants rise and fall with the tides. You can visit the Wild Gardens of Acadia for an up-close look at native plants or join a ranger for one of our many guided walks.
 
Tree roots and moss along a forest floor
The diversity of Acadia National Park is reflected in its plant life; more than 1,100 plant species are found here.
 

Ecosystems: From Summit to Sea

Taken all together, the land and sea and the plant and animal life form unique natural environments called ecosystems. Along with geologic features like glacial erratics and cobblestone beaches, these ecosystems are Acadia. It is a place forged in the fire of ancient volcanoes and carved by ice. Acadia is rarely flat ground, from the sculpted granite mountains with summits and cliffs to the glacially-scoured lake beds and stream valleys. At the base of the mountains, the land is dotted with wetlands or continues it slope down to rocky headlands that have been undergoing a ongoing assault by the weather and the sea since their formation.
 
 

Enjoy the View: Night Skies and Scenic Views

Acadia possesses remarkably dark skies for its proximity to Portland, Boston, and New York. The Milky Way dazzles visitors and reminds us just how large our “home” galaxy truly is. When the moon is full, the light it reflects from the sun is so bright it can cast a glow across the ocean. During the day, both the motor road system and the (non-motorized) carriage road system at the park were carefully laid out by prominent landscape architects to take advantage of spectacular views. From the top of the mountains or on one of the park's many historic hiking trails, enjoying the view is one of the key experiences in Acadia. Both of these incredible Acadia visual experiences are constantly under threat from light pollution and air pollution. Learn more about what can do to protect the view.
 
 

Environmental Threats

Climate change is rapidly changing Acadia's environment. Rising temperatures, warming waters, rising seas, and extreme weather events are increasing environmental stress leaving plants, animals, and ecosystems more suceptable to damage, as well as pests and disease. Among the greatest environmental challenges facing Acadia National Park is the presence and threat of invasive species. Non-native species, especially those considered invasive plants or invasive animals, threaten communities of native plants and animals across the United States. Located along the mid-coast of Maine, Acadia is downwind from large urban and industrial areas in states to the south and west. Periodically, high concentrations of air pollutants blow into the park from these areas and create hazy views and unsafe breathing conditions. Coupled with overtourism, the environment of Acadia is threatened on various fronts. Federally threatened or endangered species are on the tip of the spear. You can help protect Acadia during your visit by following all posted signs and regulations, riding the Island Explorer or carpooling, and following Leave No Trace principles. Learn more about the environmental theats that face Acadia National Park.
 
 

How Does It Work?: Natural Processes and Concepts

Behind the beauty of Acadia is a fascinating sets of processes at work. The geologic history of Acadia National Park stretches back in time through millions of years to the formation of the oldest rocks on Mount Desert Island and continues to the present with the persistent forces of wind and weather which cause erosion. Evidence of this rich geologic past can be seen across the island, along rocky shorelines and atop windswept mountains. The tides shape Acadia on their twice daily rise and fall. Wildland fire has shaped the natural disturbance of the plants and animals of Acadia from the earliest lightning strike to more recent human activity for agriculture and fire prevention. The result of all these processes at work is an Acadia that is rich in biodiversity - the collective plant, animal, and microbiotic world.

 
 

All Species List

You can see a complete list of species and other reports on the National Park Service Integrated Resources Management Application.
 

More About Nature in Acadia

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    Last updated: July 29, 2026

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