Types of Beavers in Wyoming
Wyoming is home to one beaver species, the North American beaver (Castor canadensis), which lives in nearly every mountain valley, river system, and wetland across the state. These semi-aquatic rodents are the second-largest living rodents and are skilled engineers that shape entire ecosystems through dam building and habitat modification. Understanding beaver identification and behavior helps you recognize active colonies during a Wyoming wildlife trip and appreciate the role they play in river health.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself.
- 1
- species recorded
- June, July, May
- peak months
Real sighting data, source iNaturalist
463 verified observations on iNaturalist of beaver have been recorded in Wyoming, most often in June, July, May.
When beaver are recorded in Wyoming
Wyoming is home to one beaver species, the North American beaver (Castor canadensis), which lives in nearly every mountain valley, river system, and wetland across the state. These semi-aquatic rodents are the second-largest living rodents and are skilled engineers that shape entire ecosystems through dam building and habitat modification. Understanding beaver identification and behavior helps you recognize active colonies during a Wyoming wildlife trip and appreciate the role they play in river health.
What is the only beaver species in Wyoming?
The North American beaver (Castor canadensis) is the single beaver species found throughout Wyoming. There are no other wild beaver species in North America, and the state has never been home to the European beaver or any other Castor species. North American beavers occur from sea level to high mountain elevations, adapting to rivers, streams, ponds, and wetlands across all Wyoming habitat types.
How big do Wyoming beavers get?
Adult North American beavers typically weigh 30 to 60 pounds, with some large males reaching up to 100 pounds. Body length from nose to rump averages 24 to 30 inches, and their flat, paddle-shaped tail adds another 8 to 12 inches. They are stocky, barrel-bodied animals that move awkwardly on land but are graceful and powerful in water.
What color are beavers and how do you tell them apart?
Beavers have brown to reddish-brown fur that appears darker when wet and lighter when dry. Their undercoat is dense and waterproof, while guard hairs on the outer layer are longer and give them a shaggy appearance. Individual beavers vary in shade from light tan to nearly black. You cannot reliably distinguish individual beaver species by color alone since only one species occurs in Wyoming. Size and habitat are better clues: beavers are much larger than muskrats or nutrias, and smaller than river otters.
What distinctive features identify a beaver?
The most recognizable beaver features are a flat, scaly paddle tail that is paddle-shaped and hairless, large orange-yellow front teeth visible even with mouth closed, and small rounded ears. Their hind feet are large and webbed for swimming, while front feet are smaller with claws for digging and manipulating wood. Look for their characteristic hunched posture when swimming, with only the head and upper back above water.
What sounds do beavers make?
Beavers are generally quiet animals but produce several vocalizations. They hiss, growl, and whine to communicate with family members, and young kits make high-pitched chirping and squeaking sounds. The most famous beaver sound is a loud tail slap against water, which serves as an alarm signal when a beaver senses danger. This sharp crack can be heard hundreds of feet away and is a reliable sign an alert beaver is in the vicinity.
What are beaver tracks and signs?
Beaver tracks show distinctive features: front prints are about 2 inches wide and show five toes arranged like human fingers, while hind prints are larger at 5 to 7 inches with a webbed appearance. Look for drag marks in mud or snow where a beaver has walked from water to feeding areas. Fresh wood shavings and peeled saplings are the most obvious beaver signs, along with dam material scattered on banks and muddy, stick-built structures in water.
Do Wyoming beavers build dams?
Yes. North American beavers are famous dam builders and construct dams across streams to raise water levels and create ponds for safety and access to vegetation. Wyoming beavers build dams year-round, though activity increases in fall as they prepare for winter. A single beaver colony can construct multiple dams of varying sizes, and the largest dams in Wyoming may span 20 to 30 feet or more. Abandoned dams persist for years and are part of the landscape.
What do beavers eat in Wyoming?
Beavers are herbivores and prefer soft woods like aspen, birch, willow, and cottonwood. In Wyoming, aspen groves are prime beaver habitat for this reason. They also eat water plants, bark, leaves, and shrubs. Beavers fell trees ranging from saplings to trees 6 inches in diameter or larger, and they cache branches underwater for winter food. An individual beaver may fell 200 or more trees per year.
What is the beaver's role in Wyoming ecosystems?
Beavers are a keystone species that dramatically reshape watersheds through dam building. Their ponds slow water flow, filter sediment, recharge groundwater, and create habitat for waterfowl, fish, and amphibians. Over time, abandoned beaver ponds fill with sediment and become meadows that support diverse plant and wildlife communities. This cycle makes beavers critical to Wyoming's wetland health and biodiversity, particularly in the mountain valleys and foothills.
When do beaver colonies reproduce?
Beavers breed in winter, typically December through February, and kits are born in spring between April and June. A typical colony includes a breeding pair and their young from one or more years. Young beavers stay with parents for about two years before leaving to establish their own territory. Wyoming populations have stable colonies, and finding one colony does not guarantee seeing beavers during a short visit.
Conservation status, source NatureServe
Conservation rank for beaver (American Beaver, Castor canadensis), as assessed by NatureServe Explorer.
| Scope | NatureServe rank | Meaning |
|---|---|---|
| In Wyoming | S4 | Apparently 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 is the only beaver species in Wyoming?+
The North American beaver (Castor canadensis) is the single beaver species found throughout Wyoming. There are no other wild beaver species in North America, and the state has never been home to the European beaver or any other Castor species. North American beavers occur from sea level to high mountain elevations, adapting to rivers, streams, ponds, and wetlands across all Wyoming habitat types.
How big do Wyoming beavers get?+
Adult North American beavers typically weigh 30 to 60 pounds, with some large males reaching up to 100 pounds. Body length from nose to rump averages 24 to 30 inches, and their flat, paddle-shaped tail adds another 8 to 12 inches. They are stocky, barrel-bodied animals that move awkwardly on land but are graceful and powerful in water.
What color are beavers and how do you tell them apart?+
Beavers have brown to reddish-brown fur that appears darker when wet and lighter when dry. Their undercoat is dense and waterproof, while guard hairs on the outer layer are longer and give them a shaggy appearance. Individual beavers vary in shade from light tan to nearly black. You cannot reliably distinguish individual beaver species by color alone since only one species occurs in Wyoming. Size and habitat are better clues: beavers are much larger than muskrats or nutrias, and smaller than river otters.
What distinctive features identify a beaver?+
The most recognizable beaver features are a flat, scaly paddle tail that is paddle-shaped and hairless, large orange-yellow front teeth visible even with mouth closed, and small rounded ears. Their hind feet are large and webbed for swimming, while front feet are smaller with claws for digging and manipulating wood. Look for their characteristic hunched posture when swimming, with only the head and upper back above water.
What sounds do beavers make?+
Beavers are generally quiet animals but produce several vocalizations. They hiss, growl, and whine to communicate with family members, and young kits make high-pitched chirping and squeaking sounds. The most famous beaver sound is a loud tail slap against water, which serves as an alarm signal when a beaver senses danger. This sharp crack can be heard hundreds of feet away and is a reliable sign an alert beaver is in the vicinity.
What are beaver tracks and signs?+
Beaver tracks show distinctive features: front prints are about 2 inches wide and show five toes arranged like human fingers, while hind prints are larger at 5 to 7 inches with a webbed appearance. Look for drag marks in mud or snow where a beaver has walked from water to feeding areas. Fresh wood shavings and peeled saplings are the most obvious beaver signs, along with dam material scattered on banks and muddy, stick-built structures in water.
Do Wyoming beavers build dams?+
Yes. North American beavers are famous dam builders and construct dams across streams to raise water levels and create ponds for safety and access to vegetation. Wyoming beavers build dams year-round, though activity increases in fall as they prepare for winter. A single beaver colony can construct multiple dams of varying sizes, and the largest dams in Wyoming may span 20 to 30 feet or more. Abandoned dams persist for years and are part of the landscape.
What do beavers eat in Wyoming?+
Beavers are herbivores and prefer soft woods like aspen, birch, willow, and cottonwood. In Wyoming, aspen groves are prime beaver habitat for this reason. They also eat water plants, bark, leaves, and shrubs. Beavers fell trees ranging from saplings to trees 6 inches in diameter or larger, and they cache branches underwater for winter food. An individual beaver may fell 200 or more trees per year.
What is the beaver's role in Wyoming ecosystems?+
Beavers are a keystone species that dramatically reshape watersheds through dam building. Their ponds slow water flow, filter sediment, recharge groundwater, and create habitat for waterfowl, fish, and amphibians. Over time, abandoned beaver ponds fill with sediment and become meadows that support diverse plant and wildlife communities. This cycle makes beavers critical to Wyoming's wetland health and biodiversity, particularly in the mountain valleys and foothills.
When do beaver colonies reproduce?+
Beavers breed in winter, typically December through February, and kits are born in spring between April and June. A typical colony includes a breeding pair and their young from one or more years. Young beavers stay with parents for about two years before leaving to establish their own territory. Wyoming populations have stable colonies, and finding one colony does not guarantee seeing beavers during a short visit.
Keep exploring
More wildlife in Wyoming