Types of Frogs in Michigan: 14 Species From Spring Peepers to Bullfrogs
November 3, 2026
Michigan’s wetlands, forests, and shorelines host a surprising amount of amphibian diversity for a state known for brutal winters. Fourteen species of frogs and toads call the Great Lakes State home, and more than 6,500 frog species exist worldwide, so Michigan’s share represents a tiny but distinctive slice of that global picture. According to the Michigan Department of Natural Resources, thirteen species of frogs and toads are found in Michigan, and they are an important part of our state’s ecosystems, with a fourteenth species, the boreal chorus frog, adding to the count on Isle Royale.
Identifying the different types of frogs in Michigan comes down to paying attention to size, skin texture, color pattern, and especially the call each species makes during breeding season. Some, like the Blanchard’s cricket frog, have become so rare that a sighting is worth reporting to state biologists. Others, like the American bullfrog, are impossible to miss once summer nights heat up. For readers curious how Michigan’s amphibians compare to warmer climates, the frog diversity found in the Amazon rainforest shows just how specialized cold-climate species have become by comparison. This guide also draws on broader research into frog classification and biology to help explain what sets each Michigan species apart.
Before diving into each species, it helps to see how they stack up side by side.
| Common Name | Family Group | Typical Adult Size | Michigan Conservation Status |
|---|---|---|---|
| American Bullfrog | True Frog | 3.6–6 in | Common, statewide |
| Green Frog | True Frog | 2–4 in | Common, statewide |
| Mink Frog | True Frog | 1.75–3 in | Common, northern Michigan |
| Wood Frog | True Frog | 1.75–3.25 in | Common, statewide |
| Northern Leopard Frog | True Frog | 2–4.5 in | Declining, statewide |
| Pickerel Frog | True Frog | 1.75–3 in | Special concern |
| Blanchard’s Cricket Frog | Treefrog | 0.6–1.5 in | Threatened |
| Eastern Gray Treefrog | Treefrog | 1.25–2 in | Common, statewide |
| Cope’s Gray Treefrog | Treefrog | 1.25–2 in | Common, statewide |
| Spring Peeper | Treefrog | 0.75–1.5 in | Common, statewide |
| Western Chorus Frog | Treefrog | 0.75–1.5 in | Common, southern/central MI |
| Boreal Chorus Frog | Treefrog | 0.75–1.5 in | Special concern, Isle Royale only |
| American Toad | True Toad | 2–3.5 in | Common, statewide |
| Fowler’s Toad | True Toad | 2–3 in | Special concern |
1. American Bullfrog
The American bullfrog (Lithobates catesbeianus) is the giant of Michigan’s frog world. The American bullfrog is the largest frog in the state, found near permanent bodies of water such as large ponds, streams, and lakes. Mature males develop a distinctive trait during breeding season: once males reach sexual maturity, their throats turn bright yellow.
Bullfrogs are frequently mistaken for green frogs, but there’s a reliable way to tell them apart. Bullfrogs don’t have a dorsal ridge down their back the way green frogs do; instead, the ridge wraps around their tympanum. Historically, overharvesting took a toll on the species. The Michigan DNR has stated that the bullfrog population has been reduced due to over-harvesting of frog legs. Bullfrogs aren’t unique to the Midwest, either; the species has become an invasive problem in places like Hawaii, where it was introduced outside its native range, a pattern documented among the frog species found in Hawaii and among warmer-climate populations covered in research on the types of frogs in Alabama.
Pro Tip: Listen for the call before you look. A bullfrog’s deep, resonant “jug-o-rum” carries across open water and is one of the easiest ways to confirm identification without getting close enough to spook it.
2. Green Frog
The green frog (Lithobates clamitans) ranks among the most commonly seen frogs in the state. The green frog is abundant throughout Michigan and is typically greenish-brown with dark mottling on its head, chest, and under its legs. Unlike the bullfrog, it carries a pair of raised ridges running down each side of its back from the eye to the hip, which is the single fastest way to separate the two species in the field.
Green frogs favor the same permanent ponds, lakes, and slow streams that bullfrogs do, and the two species often share the same shoreline. Their call sounds like a single loose banjo string being plucked, a sharp contrast to the bullfrog’s low growl. Breeding runs from late spring through midsummer, and tadpoles can take over a year to fully develop before metamorphosis.
3. Mink Frog
The mink frog (Lithobates septentrionalis) earns its name from a musky odor it releases when handled, reminiscent of the scent glands of a mink. This species prefers cooler, well-oxygenated water than most other Michigan ranids, so it’s concentrated in the Upper Peninsula and the northern half of the Lower Peninsula rather than the warmer southern counties.
Mink frogs are often confused with green frogs because both share a similar olive-to-brown base color with dark blotching. The mink frog’s spots tend to be more irregular and its skin has a slightly rougher texture. Anyone curious how northern-adapted amphibians compare across state lines might also look at the frog species documented in Maine, where similarly cold-tolerant populations persist in boreal wetlands.
4. Wood Frog
Few Michigan amphibians are more remarkable than the wood frog (Lithobates sylvaticus). It’s a modestly sized, tan-to-brown frog with a dark “robber’s mask” marking that runs from its snout through each eye, and it breeds explosively in temporary vernal pools as soon as the ice begins to melt, often weeks before most other species stir.
What makes the wood frog exceptional is its winter survival strategy. Wood frogs, along with chorus frogs and treefrogs, produce special “anti-freeze” substances in their bodies that allow them to survive while buried in shallow soil and leaf litter. This lets the frog’s body partially freeze solid during cold snaps and thaw out again unharmed come spring, a trait that lets it range farther north than almost any other North American frog.
Key Insight: Wood frogs convert glycogen stored in their liver into glucose when temperatures drop, flooding their cells with a natural antifreeze that prevents ice crystals from causing lethal damage.
5. Northern Leopard Frog
The northern leopard frog (Lithobates pipiens) is named for the rounded, dark spots scattered across its green or brown back, each ringed with a lighter halo. It favors wet meadows, marshes, and grassy pond edges more than deep open water, and it will range surprisingly far from a water source during summer rains.
This species was once one of the most abundant frogs statewide, but populations have thinned considerably over the past several decades, a trend tracked by citizen-science projects like the Michigan Herp Atlas. Habitat loss, disease, and pesticide exposure are the most commonly cited factors behind the decline. For a look at how leopard frog relatives fare in other regions, the frog species found in Connecticut offer a useful East Coast comparison.
6. Pickerel Frog
The pickerel frog (Lithobates palustris) looks similar to the northern leopard frog at a glance, but its spots are squarer and arranged in two fairly neat rows down the back rather than scattered randomly. Bright yellow-orange coloring on the inner thighs, visible when the frog hops, is the giveaway feature that separates it from every other Michigan species.
Unusually for a North American frog, the pickerel frog carries mildly toxic skin secretions. The pickerel frog is the only poisonous frog living in Michigan, and predators that can tolerate other frogs often avoid it. The species is listed as a special concern in the state. The pickerel frog is a species of special concern in Michigan. Readers interested in toxic amphibians more broadly can compare this mild case against the far more potent species covered in a guide to poisonous frogs around the world.
7. Blanchard’s Cricket Frog
Blanchard’s cricket frog (Acris blanchardi) is Michigan’s rarest and smallest frog species, and its decline has made it something of a conservation priority for state biologists. It is a small, dark colored frog that is threatened or endangered in Michigan, Wisconsin, and Minnesota, and in Michigan specifically, the Blanchard’s cricket frog is a threatened species.
The species favors open, muddy, or sandy shorelines of permanent ponds and lakes, where it often rests on floating algae mats or lily pads. Any sightings should be reported to the DNR, and the frogs tend to breed in quiet water near ponds, lakes, and adjacent streams. Populations crashed starting in the late 1970s. A significant population decline has occurred since the late 1970s, with habitat loss and chemical contaminants posited as the leading causes, and surviving colonies are now largely restricted to the southern and western portions of the Lower Peninsula. There’s cautious optimism in recent research, though: some Blanchard’s cricket frog populations have been expanding northward over the past two decades in parts of the upper Midwest, according to a study published in the Journal of Herpetology. The species was named for herpetologist Frank Nelson Blanchard, as Wikipedia notes; the frog is named after herpetologist and professor of zoology at Michigan Frank Nelson Blanchard. Its southern range extends well beyond Michigan, overlapping with populations covered in the guide to frog species in Oklahoma.
Important Note: Michigan’s Blanchard’s cricket frog population has been documented at only a handful of sites statewide. If you believe you’ve spotted one, note the exact location and report it through the Michigan Natural Features Inventory or the DNR.
8. Eastern Gray Treefrog
The eastern gray treefrog (Hyla versicolor) is a master of camouflage, able to shift its skin tone between gray, green, and brown depending on the surface it’s resting on, often taking on a mottled, lichen-like pattern that makes it nearly invisible against tree bark. Sticky toe pads let it climb vertical surfaces and cling to leaves well above ground, which is where most people encounter its calls rather than the frog itself.
This species is common across the entire state and tolerant of a wide range of habitats, from suburban backyards to deep forest wetlands. Its call is a slow, musical trill that can last several seconds, often heard on warm, humid evenings. Treefrog diversity elsewhere in the country looks quite different; the treefrog species found in California include several desert-adapted specialists with no direct Michigan equivalent.
9. Cope’s Gray Treefrog
Cope’s gray treefrog (Hyla chrysoscelis) is virtually identical to the eastern gray treefrog in size, shape, and color, which makes call, not appearance, the most dependable way to separate the two. The two species can be difficult to tell apart during breeding while both are mottled, though Cope’s gray treefrog most often shows a solid lime-green back.
The clearest distinction comes down to sound. Cope’s gray treefrog’s call is short and raspy, compared with the slower, more musical trill of its near-identical cousin. The two species are so closely related that they can only reliably be told apart genetically. Southern populations of similarly paired treefrog species show up in the guide to frog species in South Carolina, where several Hylidae relatives overlap in range.
10. Spring Peeper
The spring peeper (Pseudacris crucifer) is one of the smallest frogs in the state and arguably its most famous, since its chorus is often the first true sound of spring across Michigan wetlands. The spring peeper is one of Michigan’s smallest frogs, measuring from 1 to 1.5 inches, and can be distinguished by the dark “X” across its back.
Despite its tiny size, a chorus of peepers calling together from a single pond can be loud enough to hear from a quarter mile away. This frog is Michigan’s most abundant species and can be found throughout the state in woods next to vegetated swamps and marshes. Peepers begin calling even before ice fully clears from shallow breeding pools, tolerating near-freezing water temperatures that would stop most other frogs cold.
11. Western Chorus Frog
The western chorus frog (Pseudacris triseriata) is named for the three dark, broken stripes that run down its back and sides against a tan or gray background. It’s a small, slender frog rarely longer than an inch and a half, and it favors open, grassy wetlands, flooded fields, and shallow marsh edges rather than dense forest.
Its call has often been compared to a thumb running along the teeth of a comb, a rising, raspy trill that’s easy to pick out once learned. The species is common across the southern and central Lower Peninsula, and it shares much of its breeding-habitat preference with grassland frog species found elsewhere, including several documented among the frog species adapted to grassland habitats.
12. Boreal Chorus Frog
The boreal chorus frog (Pseudacris maculata) looks almost identical to its western chorus frog cousin, sharing the same small size and striped pattern, but the two species occupy very different parts of Michigan. Adults are approximately 1.5 inches long and colored pale gray or brown, with a few individuals being red or bright green.
In Michigan, this species has an unusually limited range. It occurs only on Isle Royale in Michigan, where it is considered a species of special concern. Statewide conservation assessments confirm the designation. The boreal chorus frog is considered to be of special concern, although it is not protected under the state’s endangered species act. Its broader North American range extends much farther west, overlapping with populations described in the guide to frog species found in Oregon.
13. American Toad
The American toad (Anaxyrus americanus) is the warty, bumpy amphibian most people picture when they hear the word “toad.” It has dry, textured skin ranging from brown to olive to brick red, with one or two enlarged warts in each dark back spot, and it moves in short hops rather than the long leaps typical of true frogs.
Unlike most of Michigan’s frogs, American toads spend the bulk of their lives on land, only returning to shallow water to breed in spring. Their long, musical trill can last up to 30 seconds and is a common backyard and garden sound statewide. Toads share garden habitat with plenty of other small wildlife, including many of the species cataloged in a guide to spiders found in Michigan.
14. Fowler’s Toad
Fowler’s toad (Anaxyrus fowleri) is the American toad’s closest relative in the state, and the two are frequently confused. Fowler’s toad is usually brown, gray, olive green, or rust red with darkened warty spots; as adults, a pale stripe forms down the back, and the belly is whitish with one dark spot.
The clearest field mark is wart count: Fowler’s toad typically shows three or more warts within each dark blotch, compared to one or two on the American toad. Its Michigan range is notably restricted. Fowler’s toads can be found within the extreme western and southern Lower Peninsula of Michigan, and the species carries conservation weight to match. The Fowler’s toad is a species of special concern in Michigan.
Common Mistake: Don’t rely on color alone to separate American and Fowler’s toads — both vary widely in shade. Count the warts inside each dark spot instead; it’s the one feature that holds up consistently in the field.
Fourteen species may not sound like much next to the frog-rich tropics, but Michigan’s amphibians pack a surprising amount of specialization into a short breeding season bookended by brutal winters. From the wood frog’s ability to freeze and thaw to the Blanchard’s cricket frog’s increasingly rare presence, each species on this list has adapted to the state’s lakes, wetlands, and woodlands in its own way. Learning a handful of calls and a few key markings is usually enough to tell most of these species apart on a single evening walk near water.
Michigan’s frogs and toads don’t exist in isolation, either. The same wetlands and woodlots that support this amphibian diversity also shelter other wildlife worth knowing, from the chipmunk species native to Michigan to the moth species that flutter through the same marshes at dusk and the ladybug species found across the state’s gardens and fields. For anyone building a broader picture of Michigan’s amphibians, the Wikipedia list of amphibians of Michigan and the Michigan State University Extension’s research on frog and toad biology are both solid starting points for deeper reading.