5 Types of Frogs in Colorado: From Freeze-Surviving Wood Frogs to Invasive Bullfrogs
September 23, 2026
Every spring in the mountains west of Fort Collins, a small brown frog thaws itself back to life after spending the winter frozen nearly solid. Types of frogs in Colorado range from that remarkable survivor to a six-inch invader that has reshaped wetland food chains across the state.
There are 17 different types of frogs in Colorado, but five of them tell the most complete story of how amphibians survive here: a freeze-tolerant native, a canyon specialist, a declining true frog now protected by wildlife officials, a destructive invader, and a burrowing toad built for drought. This guide covers the calls, colors, and habitats naturalists are most likely to encounter from the Front Range to the Western Slope. Readers curious about how these Colorado natives compare to different types of frogs elsewhere in North America, or exactly how many frog species exist worldwide, will find each Colorado species fits into a much bigger amphibian picture.
1. Wood Frog
The wood frog (Lithobates sylvaticus) is best known for a survival trick that sounds more like science fiction than biology. It has adapted to cold climates by being able to freeze over the winter, when breathing and heartbeat stop and the body produces a type of antifreeze that keeps its cells from bursting. In the spring, it thaws and begins feeding again.
Wood frogs have a wide range of coloration, including various shades of brown, gray, red, or green, with females tending to be more brightly colored. One distinct identifying feature is the black marking across the eyes, which resembles a mask. Adult body lengths range from 1.5 to 3.25 inches.
Wood frogs are found in northern Colorado in moist woodland habitats, including forested swamps, ravines, and bogs. They also turn up in the mountains surrounding North Park, at elevations of roughly 7,000 to 9,800 feet. Because they range so widely across cold parts of North America, similar cold-adapted survival strategies also show up among the frogs found in Utah, another state with harsh mountain winters.
Wood frogs are among the first amphibians to emerge after the snow melts, and their distinctive call sounds like a clucking chicken heard near vernal pools and other small bodies of water. They also seem able to recognize their own family — as tadpoles, siblings will seek each other out and group together rather than mixing with unrelated tadpoles. According to The Frog Lady’s Colorado field notes, wood frogs share their high-elevation range with only a handful of other amphibians tough enough to handle the state’s short growing season.
2. Canyon Treefrog
The canyon treefrog (Hyla arenicolor) trades wet forests for exposed rock, making it one of the more specialized frogs on this list. It is often found in rocky areas and canyons, and its blotchy gray or tan skin blends almost perfectly with the sandstone and granite surfaces it climbs — which is often why hikers hear one before they ever see it.
The canyon treefrog can be found within the western and southwestern areas of Colorado. It breeds in pools alongside streams primarily in spring, though it has also been known to breed after heavy summer rains. That opportunistic breeding pattern lets it take advantage of Colorado’s unpredictable monsoon storms, which can fill canyon pools within a matter of hours.
Canyon treefrogs are far more common across the desert Southwest than in Colorado, where the state sits at the edge of their range. Anyone comparing populations to the larger numbers found among frogs in Arizona will notice the same rock-dwelling behavior, just spread across a bigger and warmer landscape.
Pro Tip: Resources like FrogWatch USA or Colorado Parks & Wildlife provide audio samples and field guides that make it easier to match a call to a species. Recording a short clip on a phone and comparing it later is often faster than trying to spot a well-camouflaged frog after dark.
3. Northern Leopard Frog
The northern leopard frog (Lithobates pipiens) is the species most people picture when they imagine a classic pond frog. It has smooth skin in shades of green, yellow-green, or brown, marked with large, dark, haloed spots. Its head and body can reach up to about 11 centimeters, or 4.3 inches, with extensive webbing on the hind toes.
It occurs nearly statewide in both mountains and lowlands, though it is scarce or absent across most of southeastern Colorado and the Republican River drainage in the northeast. That gap sits close to areas covered by this guide to frogs found in Nebraska, since the same river drainage crosses the state line.
Important Note: The northern leopard frog is considered a species of concern by Colorado Parks and Wildlife and has been ranked a Tier 1 Species of Greatest Conservation Need, according to reporting on the frog’s declining status and confirmed on the Colorado Parks and Wildlife species page. Taking or possessing one in Colorado is prohibited without a special license for scientific collecting, rehabilitation, education, or propagation.
The once-abundant species has become scarce in many areas because of habitat destruction, drought, and colonization by non-native American bullfrogs. Declines have been especially severe in western North America, and while the frog is not federally listed under the Endangered Species Act, it is treated as a species of greatest conservation need in many western states. The U.S. Fish and Wildlife Service now supports restoration projects aimed at reversing that trend.
4. American Bullfrog
The American bullfrog (Lithobates catesbeianus) is the giant of Colorado’s frog world, and one of the state’s biggest amphibian problems. Adult body lengths range from 3.6 to 6 inches, with coloration typically olive green — though some individuals show gray or brown mottling — fully webbed back feet, and a weight that can reach as much as 1.5 pounds, according to Bird Watching HQ’s Colorado frog guide.
Bullfrogs naturally occur in the eastern half of the state, but they have also been introduced to parts of western Colorado, where their oversized appetites can be destructive to native ecosystems. Colorado wildlife officials classify the bullfrog as an introduced and invasive species statewide.
Bullfrogs live in permanent bodies of water, including swamps, ponds, and lakes, and they can harm native wildlife by eating smaller frogs, fish, and even birds. Introduced populations compete with and prey on native species, adding to pressure already caused by habitat loss and disease. The species is native much farther east, including across wetlands covered in this guide to frogs in Illinois, where it fills a very different ecological role than it does out west.
| Species | Average Size | Primary Colorado Habitat | Notable Status |
|---|---|---|---|
| Wood Frog | 1.5–3.25 inches | High-elevation woodlands and vernal pools, northern Colorado | Freeze-tolerant native |
| Canyon Treefrog | Small, rock-dwelling | Rocky canyons, western and southwestern Colorado | Native, limited range |
| Northern Leopard Frog | Up to 4.3 inches | Ponds and wetlands, nearly statewide | Species of concern / Tier 1 SGCN |
| American Bullfrog | 3.6–6 inches | Permanent ponds, lakes, and swamps | Introduced and invasive |
| Plains Spadefoot Toad | Small, round-bodied | Sandy grasslands and temporary pools | Native, secretive burrower |
5. Plains Spadefoot Toad
The plains spadefoot toad (Spea bombifrons) spends most of its life out of sight, which is exactly why it belongs on this list. It favors areas with loose, sandy soil that make burrowing easy, spending most of its life underground and coming out only to breed and hunt, according to SnakeTracks’ Colorado species profile.
Small and round-bodied, it ranges from tan to dark brown and gets its name from the dark, spade-shaped structure on each hind foot that it uses to dig. Orange spots and black markings cover its back, and its large eyes have distinctive orange, cat-like pupils, which is part of why the species is secretive and rarely seen.
It breeds in water sources near its burrows during rainy seasons and will not emerge in dry periods, since it needs to stay moist and, like other frogs, absorbs water through its skin rather than drinking it. This drought-triggered breeding pattern is common among spadefoot species across the arid West and sets the plains spadefoot apart from the pond-bound frogs described earlier in this guide.
Common Mistake: Calling every spadefoot a true toad. Toads are often confused with frogs, but they usually have drier, bumpier skin and shorter legs, and they tend to spend more time on land than frogs. Spadefoot toads split the difference — smoother-skinned than a typical toad but built with the same burrowing habits people associate with one.
Comparing burrowing survival strategies across regions highlights how differently frogs adapt to local conditions. For a broader look at defensive traits, including species that rely on toxic skin secretions rather than burrowing, and for a look at amphibians shaped by an entirely different climate, the frogs covered in this guide to frogs in Hawaii face conditions nothing like Colorado’s arid grasslands.
Colorado’s frogs show how differently amphibians can adapt to the same state. Some, like the wood frog, dig in and outlast winter by nearly stopping their own biology, while others, like the plains spadefoot toad, wait out drought underground and reappear after a single storm. The northern leopard frog’s decline is a reminder that even a once-common species can become a conservation priority within a few decades, and the American bullfrog shows how one introduced species can tip that balance further.
Good places to look include state parks such as North Park and areas around Grand County, southeastern marshes, and national parks like Great Sand Dunes and Colorado National Monument, along with urban wetlands such as Boulder County’s Webster Pond. Spring and early summer evenings tend to be the most productive times, since frogs are most active during the breeding season.
Frogs are only one part of Colorado’s wetland and grassland wildlife. Readers building out a fuller picture of the state’s smaller residents might also look into the bees found across Colorado or the seasonal butterflies that share the same meadows many of these frogs call home.