Are There Bullfrogs in Wyoming?
Bullfrogs are not naturally established in Wyoming and are not found in the wild throughout the state. Wyoming's high elevation, cold climate, and predominantly arid landscape make it unsuitable for these aquatic frogs. However, understanding bullfrog biology and their eastern range provides valuable context for appreciating Wyoming's unique native amphibians and wetland ecosystems.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated August 6, 2026.
Bullfrogs are not naturally established in Wyoming and are not found in the wild throughout the state. Wyoming's high elevation, cold climate, and predominantly arid landscape make it unsuitable for these aquatic frogs. However, understanding bullfrog biology and their eastern range provides valuable context for appreciating Wyoming's unique native amphibians and wetland ecosystems.
Where Bullfrogs Are Found in Wyoming
Bullfrogs do not occur naturally anywhere in Wyoming. The state's geography and climate are simply incompatible with their requirements. Wyoming's average elevation of 6,700 feet makes it the second-highest state in the nation, with many areas far exceeding this average. Bullfrogs require warm temperatures, long growing seasons, and permanent bodies of water with adequate vegetation. Wyoming's harsh winters, short summers, and arid conditions do not support bullfrogs. Bullfrogs' natural range spans the eastern United States from the Great Lakes southward through the Mississippi River drainage. Their western limit extends only to the Great Plains and isolated areas of the western edge of Kansas and Colorado. Wyoming lies well outside this range. No populations of bullfrogs have been documented in the state, and accidental introductions are extremely unlikely given the difficulty of transporting live bullfrogs across such distance. If you are interested in learning about frogs that do live in Wyoming, theWyoming wildlife hubprovides information about native amphibian species. Thenational wildlife resourcedocuments bullfrogs and other species across their actual ranges.
Season and Timing
Since bullfrogs do not live in Wyoming, seasonal patterns do not apply to the state. However, understanding when bullfrogs are active elsewhere provides context for why Wyoming's climate is unsuitable. Bullfrogs require water temperatures above 50 degrees Fahrenheit to emerge from hibernation, and they remain active through fall until freezing. Wyoming's cold season is far longer and more severe than the conditions bullfrogs tolerate. Most of Wyoming experiences freezing temperatures from October through April or longer, with water bodies remaining frozen solid for half the year or more. Bullfrogs need extended growing seasons to develop from eggs to adult frogs, typically requiring five or more years to reach maturity. Wyoming's short summers do not provide this timeframe. Mountain snowpack persists into summer across much of the state, keeping water temperatures cold even in midsummer. The combination of deep frost and brief summers makes Wyoming fundamentally incompatible with bullfrog survival. Even the relatively mild areas of Wyoming, such as portions of the Bighorn Basin and northwestern lowlands, experience conditions too harsh for bullfrogs. Understanding Wyoming's actual climate demonstrates why these large aquatic frogs remain absent from the state.
How to Identify Bullfrogs
Bullfrogs are the largest frog species in North America, reaching up to six inches in body length. They have smooth, shiny skin in shades of green to olive brown, with a large circular tympanum, or ear disc, positioned prominently behind the eye. The throat of males is yellow, while females have a lighter throat. Their legs are powerfully built with fully webbed feet adapted for swimming. The distinctive call is a deep, resonant sound resembling a human voice saying jug-o-rum or onk-onk, quite different from any Wyoming frog call. Tadpoles are large and greenish, reaching four inches in length. Bullfrogs have a stocky, useful build that distinguishes them from more slender frog species. If someone ever claimed to have seen a bullfrog in Wyoming, the accurate identification would be extremely valuable, though the claim would be extraordinary. The large size and distinctive appearance make bullfrogs unmistakable if they were ever encountered in Wyoming, which is extremely unlikely. You can learn about Wyoming's actual frog species through theWyoming wildlife guideand compare their characteristics to bullfrogs.
Where Bullfrogs Concentrate
Bullfrogs concentrate in warm, productive wetland systems with extensive emergent vegetation, conditions that do not exist in Wyoming. Bullfrogs require permanent bodies of water deep enough to not freeze solid, with cattails, lily pads, and other aquatic plants. Wyoming's wetlands are more limited and often experience complete freeze-thaw cycles that prevent permanent water from persisting. Bullfrogs favor marshes, the backwaters of large rivers, and the margins of productive lakes. These habitats exist in the eastern United States, the Mississippi River system, and scattered locations in the central plains. Wyoming's most important wetlands include the Yellowstone Lake and River system, various irrigation ponds and reservoirs, and smaller mountain wetlands. However, Wyoming's water bodies remain too cold and are too temporary or subject to harsh winter conditions for bullfrogs. Smaller water sources in Wyoming often dry up seasonally. Mountain wetlands freeze solid in winter. Even large reservoirs and rivers in Wyoming do not support the warm-water conditions bullfrogs require for successful breeding and survival. Thewildlife resource pagesdocument where bullfrogs do thrive in warmer regions of North America.
Typical Bullfrog Behavior
Bullfrogs are solitary ambush predators that remain motionless waiting for prey to approach within striking distance. They feed on insects, small fish, crayfish, and smaller frog species. At night, they rest at water's edge or on floating vegetation, while during daylight they stay submerged watching for movement. Male bullfrogs are highly territorial and aggressive, defending small areas of wetland through powerful vocalizations and physical confrontations. Their calls serve to attract mates and warn rival males away from their territory. Bullfrogs are excellent swimmers and can move rapidly through water using their powerful hind legs. They spend winter dormant in deep water, emerging in spring to establish territories and breed. Their natural lifecycle requires warm temperatures, productive habitat, and an extended growing season not available in Wyoming. Bullfrogs are primarily nocturnal, doing most of their hunting under cover of darkness. They live solitary lives except during breeding season. Their large size and predatory nature allow them to dominate smaller frogs in their range. These behaviors are adapted to eastern and central North American wetland environments very different from Wyoming.
Coexistence and Safety Notes
Bullfrogs are not part of Wyoming's wildlife and therefore Wyoming hunting and fishing regulations do not include provisions for collecting them. Wyoming's native frog species are protected under state wildlife laws, and the Wyoming Game and Fish Department manages them carefully. Wyoming has six native amphibian species adapted to the state's unique environment. These species include the northern leopard frog, chorus frogs, treefrogs, and spadefoot toads. Bullfrogs introduced outside their native range have been documented causing harm to native amphibian populations by preying on smaller frog species and competing for resources. Wyoming's native frogs have no evolutionary adaptation to bullfrogs, as the two have never coexisted in the state. If a bullfrog were ever encountered in Wyoming, it would represent an unusual occurrence and should be reported to the Wyoming Game and Fish Department for documentation. Protecting Wyoming's native amphibians is important for maintaining the state's ecological integrity. TheWyoming wildlife hubprovides information about managing and observing Wyoming's unique native frogs. Wyoming's amphibian communities are well-adapted to the state's arid and alpine conditions and do not compete with bullfrogs.
Common Species People Confuse with Bullfrogs
Wyoming does not have bullfrogs, so confusion is not an issue in practice. However, the northern leopard frog is Wyoming's largest native frog species and sometimes causes people to wonder if it might be a small bullfrog. Leopard frogs are significantly smaller than bullfrogs, rarely exceeding three inches, and have distinctive round spots rather than the plain coloring of bullfrogs. Wyoming chorus frogs are tiny, often less than an inch long, and produce a distinctive creaking call unlike any bullfrog sound. Pacific treefrogs in northwestern Wyoming are small, bumpy-textured, and produce a clicking call, not the deep bellow of a bullfrog. Spadefoot toads have bumpy, warty skin and are terrestrial rather than aquatic, differing dramatically from smooth aquatic bullfrogs. Great Plains toads are also terrestrial and warty. The Montana toad is another warty terrestrial species present in northern Wyoming. Wyoming's amphibians have evolved to thrive in the state's arid and high-elevation environment, making them fundamentally different from warm-water bullfrogs. Understanding Wyoming's native amphibian diversity illustrates why the warmer-climate bullfrog does not occur in the state. Thenational wildlife resourceprovides comparative information on frog species across different regions.
Frequently Asked Questions
Why do bullfrogs not live in Wyoming? Bullfrogs require warm temperatures, long growing seasons, and permanent warm water bodies. Wyoming's high elevation, short summers, harsh winters, and arid climate prevent bullfrogs from surviving. The state's water bodies freeze solid in winter, preventing the hibernation strategy bullfrogs use. Could bullfrogs survive if introduced to Wyoming? No, deliberate or accidental introductions to Wyoming would fail. Bullfrogs cannot tolerate Wyoming's winter temperatures or short growing season. They would not survive the first winter in most locations. What Wyoming frogs can people see instead? Wyoming has six native frog species including northern leopard frogs, chorus frogs, treefrogs, and spadefoot toads. These species are perfectly adapted to Wyoming's environment. Are bullfrogs found anywhere in the Rocky Mountains? Bullfrogs are found in isolated locations in western Colorado at lower elevations where conditions permit. They do not occur in the high mountain regions of Colorado, Utah, Montana, or Wyoming where elevation and cold eliminate suitable habitat.
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