Types of Beavers in Maryland
There is only one beaver species in Maryland: the American Beaver, North America's largest rodent. Found throughout the state in freshwater habitats from small streams to large reservoirs, American Beavers are highly recognizable by their massive size, flat paddle tail, and prominent front teeth. They are the primary architects of wetland ecosystems, creating dams, lodges, and channels that benefit countless other wildlife. Peak activity occurs during spring and early summer when beavers emerge from winter dormancy to feed and repair their structures.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself.
- 1
- species recorded
- April, March, May
- peak months
Real sighting data, source iNaturalist
2,554 verified observations on iNaturalist of beaver have been recorded in Maryland, most often in April, March, May.
When beaver are recorded in Maryland
There is only one beaver species in Maryland: the American Beaver, North America's largest rodent. Found throughout the state in freshwater habitats from small streams to large reservoirs, American Beavers are highly recognizable by their massive size, flat paddle tail, and prominent front teeth. They are the primary architects of wetland ecosystems, creating dams, lodges, and channels that benefit countless other wildlife. Peak activity occurs during spring and early summer when beavers emerge from winter dormancy to feed and repair their structures.
What does the American Beaver look like?
The American Beaver is unmistakable: adults weigh 40 to 60 pounds and measure 3 to 4 feet long, with a distinctive flat, scaly tail used for swimming and balance. Their fur is dense and waterproof, ranging from reddish-brown to nearly black. The most obvious feature is their two large front incisors, which never stop growing and are stained orange from constant use. Their eyes and ears are positioned high on the head, allowing them to see and hear while mostly submerged. Their hind feet are large and webbed for powerful swimming.
How do you distinguish American Beavers from other rodents in Maryland?
No other rodent in Maryland approaches the beaver's size or habitat footprint. Groundhogs and muskrats are the next-largest rodents, but groundhogs are terrestrial and much smaller (4 to 9 pounds), while muskrats are semi-aquatic and weigh only 2 to 4 pounds. The beaver's flat paddle tail is instantly distinctive: muskrats have thin, rat-like tails. Beavers build large dams and lodges from felled trees; muskrats dig burrows in existing banks. Once you spot a freshly felled tree, bark-stripped branches, or a dam structure, you know beavers are present.
Why do beavers have those large front teeth?
Beaver incisors are specialized tools for felling trees and stripping bark. Unlike human teeth, beaver incisors continue to grow throughout life and are self-sharpening: the outer enamel layer wears away faster than the soft dentin inside, creating a perpetually sharp, chisel-like edge. This allows them to cut through trees up to several feet in diameter. The teeth are orange because the enamel contains iron, which makes it extremely hard and durable. Beavers also use their front teeth to carry construction materials, manipulate branches, and defend themselves.
Are there any subspecies of American Beavers in Maryland?
All American Beavers in Maryland belong to a single subspecies, Castor canadensis canadensis, the eastern North American form. This subspecies ranges from the Atlantic coast west to the Rockies and was once hunted to near extinction for its fur. Thanks to reintroduction and protection efforts, it has recovered across much of its historic range, including Maryland. You will not encounter any visual differences between beavers in Maryland and those elsewhere in the eastern United States.
What time of year are beavers most active in Maryland?
Beavers in Maryland are most active from March through May, when water levels are highest and food is abundant after winter. However, they remain active year-round, never truly hibernating. In winter, they rely on cached branches stored underwater and fat reserves to survive. Summer and fall are productive building seasons, as beavers reinforce dams and lodges before colder weather. The most dramatic activity occurs at dawn and dusk, though nighttime is their primary feeding and construction time.
How many American Beavers live in Maryland?
Population surveys do not provide exact counts, but beaver presence has increased substantially since the 1990s. iNaturalist records show over 2,500 verified observations of American Beavers across Maryland, with confirmed sightings in every county. They are no longer rare or endangered in the state. Restoration of wetlands and reduced trapping pressure have allowed populations to expand into suitable habitats throughout freshwater systems.
Where in Maryland do American Beavers live?
American Beavers occupy a wide range of freshwater habitats in Maryland, including rivers, streams, creeks, swamps, marshes, and man-made reservoirs. They prefer areas with woody vegetation and stable water levels. Key populations occur in the Patuxent River system, Blackwater National Wildlife Refuge, tributaries of the Potomac River, and the Catoctin Mountains. They also inhabit smaller streams and agricultural ponds across central and western Maryland. Urban and suburban areas with adequate water and trees can support beavers, though they avoid highly developed zones.
How did beavers return to Maryland?
American Beavers were trapped to extinction in Maryland by the 1800s due to the fur trade. Recolonization began naturally as protected beaver populations from neighboring states and reintroduction programs expanded their range northeastward. By the early 2000s, beavers had re-established throughout the state. Today, they are a common sight in suitable habitat and are considered a keystone species because their dams create wetlands that benefit birds, fish, amphibians, and plants. Their return marks a success story in wildlife restoration.
Do I need to identify male versus female beavers in the field?
Visually distinguishing male and female beavers is extremely difficult without close inspection or trapping data. Females may appear slightly smaller, but size variation among individuals overlaps considerably. Both sexes have anal scent glands (castor glands) used to mark territory. The most reliable identification method is observing reproductive behavior, such as a female with kits or a pair working together on dam construction. Field guides typically do not provide reliable visual differences for live beaver sexing.
Are there beavers in your state?
Maryland beavers are present throughout the state in freshwater wetlands, streams, rivers, and reservoirs. The trunk guide 'Where to See Beavers in Maryland' covers top viewing locations such as Blackwater National Wildlife Refuge, the Patuxent River system, and Catoctin Mountain. Visit that guide for specific access points, seasonal timing, and trip planning advice.
Conservation status, source NatureServe
Conservation rank for beaver (American Beaver, Castor canadensis), as assessed by NatureServe Explorer.
| Scope | NatureServe rank | Meaning |
|---|---|---|
| In Maryland | S5 | Secure |
| Global (rangewide) | G5 | Secure |
NatureServe ranks run from 1 (critically imperiled) to 5 (secure). See our data methodology for how this is sourced.
Frequently asked questions
What does the American Beaver look like?+
The American Beaver is unmistakable: adults weigh 40 to 60 pounds and measure 3 to 4 feet long, with a distinctive flat, scaly tail used for swimming and balance. Their fur is dense and waterproof, ranging from reddish-brown to nearly black. The most obvious feature is their two large front incisors, which never stop growing and are stained orange from constant use. Their eyes and ears are positioned high on the head, allowing them to see and hear while mostly submerged. Their hind feet are large and webbed for powerful swimming.
How do you distinguish American Beavers from other rodents in Maryland?+
No other rodent in Maryland approaches the beaver's size or habitat footprint. Groundhogs and muskrats are the next-largest rodents, but groundhogs are terrestrial and much smaller (4 to 9 pounds), while muskrats are semi-aquatic and weigh only 2 to 4 pounds. The beaver's flat paddle tail is instantly distinctive: muskrats have thin, rat-like tails. Beavers build large dams and lodges from felled trees; muskrats dig burrows in existing banks. Once you spot a freshly felled tree, bark-stripped branches, or a dam structure, you know beavers are present.
Why do beavers have those large front teeth?+
Beaver incisors are specialized tools for felling trees and stripping bark. Unlike human teeth, beaver incisors continue to grow throughout life and are self-sharpening: the outer enamel layer wears away faster than the soft dentin inside, creating a perpetually sharp, chisel-like edge. This allows them to cut through trees up to several feet in diameter. The teeth are orange because the enamel contains iron, which makes it extremely hard and durable. Beavers also use their front teeth to carry construction materials, manipulate branches, and defend themselves.
Are there any subspecies of American Beavers in Maryland?+
All American Beavers in Maryland belong to a single subspecies, Castor canadensis canadensis, the eastern North American form. This subspecies ranges from the Atlantic coast west to the Rockies and was once hunted to near extinction for its fur. Thanks to reintroduction and protection efforts, it has recovered across much of its historic range, including Maryland. You will not encounter any visual differences between beavers in Maryland and those elsewhere in the eastern United States.
What time of year are beavers most active in Maryland?+
Beavers in Maryland are most active from March through May, when water levels are highest and food is abundant after winter. However, they remain active year-round, never truly hibernating. In winter, they rely on cached branches stored underwater and fat reserves to survive. Summer and fall are productive building seasons, as beavers reinforce dams and lodges before colder weather. The most dramatic activity occurs at dawn and dusk, though nighttime is their primary feeding and construction time.
How many American Beavers live in Maryland?+
Population surveys do not provide exact counts, but beaver presence has increased substantially since the 1990s. iNaturalist records show over 2,500 verified observations of American Beavers across Maryland, with confirmed sightings in every county. They are no longer rare or endangered in the state. Restoration of wetlands and reduced trapping pressure have allowed populations to expand into suitable habitats throughout freshwater systems.
Where in Maryland do American Beavers live?+
American Beavers occupy a wide range of freshwater habitats in Maryland, including rivers, streams, creeks, swamps, marshes, and man-made reservoirs. They prefer areas with woody vegetation and stable water levels. Key populations occur in the Patuxent River system, Blackwater National Wildlife Refuge, tributaries of the Potomac River, and the Catoctin Mountains. They also inhabit smaller streams and agricultural ponds across central and western Maryland. Urban and suburban areas with adequate water and trees can support beavers, though they avoid highly developed zones.
How did beavers return to Maryland?+
American Beavers were trapped to extinction in Maryland by the 1800s due to the fur trade. Recolonization began naturally as protected beaver populations from neighboring states and reintroduction programs expanded their range northeastward. By the early 2000s, beavers had re-established throughout the state. Today, they are a common sight in suitable habitat and are considered a keystone species because their dams create wetlands that benefit birds, fish, amphibians, and plants. Their return marks a success story in wildlife restoration.
Do I need to identify male versus female beavers in the field?+
Visually distinguishing male and female beavers is extremely difficult without close inspection or trapping data. Females may appear slightly smaller, but size variation among individuals overlaps considerably. Both sexes have anal scent glands (castor glands) used to mark territory. The most reliable identification method is observing reproductive behavior, such as a female with kits or a pair working together on dam construction. Field guides typically do not provide reliable visual differences for live beaver sexing.
Are there beavers in your state?+
Maryland beavers are present throughout the state in freshwater wetlands, streams, rivers, and reservoirs. The trunk guide 'Where to See Beavers in Maryland' covers top viewing locations such as Blackwater National Wildlife Refuge, the Patuxent River system, and Catoctin Mountain. Visit that guide for specific access points, seasonal timing, and trip planning advice.
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