Are There Bullfrogs in Minnesota?
Yes, bullfrogs are found in Minnesota, though populations are concentrated in the southern half of the state where conditions are warmer. These large frogs live in ponds, lakes, and marshes, reaching the northern edge of their natural range here. Minnesota's cooler climate means bullfrogs are less abundant than in warmer states. Southern Minnesota provides the most reliable bullfrog habitat.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated August 6, 2026.
Yes, bullfrogs are found in Minnesota, though populations are concentrated in the southern half of the state where conditions are warmer. These large frogs live in ponds, lakes, and marshes, reaching the northern edge of their natural range here. Minnesota's cooler climate means bullfrogs are less abundant than in warmer states. Southern Minnesota provides the most reliable bullfrog habitat.
Where Bullfrogs Are Found in Minnesota
Bullfrogs in Minnesota are concentrated primarily in the southern and central regions of the state, with populations becoming rare or absent in the far north. Southern Minnesota counties including Hennepin, Ramsey, Carver, and Scott counties around the Minneapolis area support healthy bullfrog populations. The Minnesota River Valley and associated wetlands from the Twin Cities southwest to the border contain productive bullfrogs. Southern lake regions including the area around the Twin Cities have abundant bullfrogs in lakes and ponds. Central Minnesota wetlands and prairie potholes support bullfrogs, though populations are less consistent than in the south. Northern Minnesota has sparse bullfrog populations, primarily in the southernmost portions. The Superior National Forest region in northeastern Minnesota lacks significant bullfrogs due to cold water temperatures and short growing seasons. Visit/wildlife/minnesotato learn about amphibian habitats across the state. Bullfrog populations are essentially absent in most of northern Minnesota and the far north central regions. The warmest ponds and lakes in southern Minnesota provide the most reliable bullfrog habitat. Seethe Bullfrog guide for Minnesotafor more.
Seasonal Timing and Activity
Bullfrogs in Minnesota have a relatively short active season, typically from mid-June through August, with some activity extending into early September in exceptionally warm years. They emerge from hibernation quite late compared to southern states, waiting for water temperatures to consistently exceed 55 degrees Fahrenheit, a threshold higher than in warmer climates. This delayed emergence reflects Minnesota's cold climate and the brief window of warm weather. Calling season is compressed into a short period, typically mid-June through July, creating an intense two-month vocalization period. Males establish territories and call aggressively during this brief window. Breeding occurs primarily in June and July, with females depositing eggs in shallow vegetated areas. Tadpole development is rapid due to time pressure from the short season, yet many tadpoles still do not complete metamorphosis until the following year. Overwintering as aquatic tadpoles is common in Minnesota bullfrogs. By August and September, calling activity ceases as water temperatures cool. Dormancy begins earlier in Minnesota than in southern states, often by early October. Winter hibernation lasts eight to nine months, one of the longest dormancy periods among bullfrogs in the eastern United States. Seethe Minnesota wildlife guidefor more.
How to Identify a Bullfrog
Bullfrogs are Minnesota's largest native frog species, measuring four to six inches in body length. Their skin is smooth and colored green to olive-brown, often with darker blotches that provide camouflage in aquatic vegetation. The most distinctive feature is the large tympanum, a circular eardrum visible behind each eye that appears as a prominent disk roughly the size of the eye itself. Males display a yellow or golden throat, while females have a white or pale throat and are generally larger than males. The bullfrog's stocky, powerful build and muscular hind legs clearly distinguish it from Minnesota's other frog species. The large tympanum is unique among Minnesota frogs and provides immediate identification. Their deep resonant call, heard mainly in June and July, is unmistakable to anyone who hears it. Juveniles are smaller but retain the characteristic large tympanum and useful body shape. When uncertain, the combination of large size, large tympanum, and smooth skin confirms that you have identified a bullfrog.
Where Sightings Concentrate in Minnesota
Bullfrogs concentrate in the warmest water bodies available in Minnesota. Shallow bays and warm-water coves of larger lakes, particularly those that warm considerably in summer, consistently harbor bullfrogs. Cattail and bulrush-dominated marshes provide preferred habitat, especially in southern Minnesota regions. Ponds connected to larger lake systems that moderate temperature changes support reliable bullfrog populations. Visit/wildlife/minnesota/bullfrogfor more detailed information about local habitats. Beaver ponds created throughout Minnesota's forested areas occasionally develop bullfrogs, particularly in southern forests. Prairie pothole wetlands in southwestern Minnesota sometimes support bullfrogs, especially in larger, deeper potholes. Spring-fed ponds with stable water levels provide stable habitat. The Minnesota River floodplain marshes consistently produce bullfrog populations. Explore/wildlifefor additional regional information about Minnesota wildlife. Cattail marshes connected to warm shallow lakes provide the most reliable bullfrog concentrations. Winter survival requires access to deep water that does not freeze solid, making lake connections essential.
Bullfrog Behavior and Diet
Bullfrogs are ambush predators that position themselves at water margins or among submerged vegetation, remaining motionless while waiting for suitable prey. They strike with a rapid tongue snap when prey approaches within striking distance. Adult bullfrogs consume insects, smaller frogs including other bullfrogs, aquatic invertebrates, and occasionally crawfish or small fish. Tadpoles feed on algae and aquatic vegetation during their aquatic phase. Minnesota bullfrogs are highly territorial, with males establishing and defending specific calling sites during the brief breeding season. Their loud vocalizations serve to establish territory and attract females. The short Minnesota summer constrains feeding time, making bullfrogs opportunistic hunters. They are primarily nocturnal but become active during warm days as well. Bullfrogs have excellent vision for detecting movement and respond to vibrations in water. They are aggressive hunters capable of consuming prey nearly their own size. By late August, as water temperatures cool, bullfrogs shift to deeper areas and prepare for the long dormancy period, settling into bottom sediments.
Coexistence and Legal Protections
Bullfrogs in Minnesota are fully protected by state wildlife laws and cannot be collected, captured, or harmed without special permits. They provide ecological services by controlling insect populations and serving as food for herons, snakes, and turtles. Bullfrogs can coexist peacefully with human activities in and around Minnesota's aquatic environments. However, they are sensitive to water pollution, acid rain impacts, pesticides, and habitat loss. Water level fluctuations from dam operations can eliminate breeding habitat for bullfrogs. Wetland drainage for agricultural expansion remains a significant threat to bullfrog populations. Climate change poses a particular challenge for Minnesota bullfrogs already at the northern edge of their range, as warmer winters may disrupt hibernation cycles. Landowners can support bullfrogs by maintaining natural wetland margins, avoiding pesticide use, and protecting shallow breeding areas. Never handle wild bullfrogs, as oils and bacteria from human hands can harm them. Minnesota's amphibian populations face multiple environmental pressures, making habitat protection efforts especially important for long-term persistence.
Species Commonly Confused with Bullfrogs
Several Minnesota frog species could potentially be mistaken for bullfrogs by those unfamiliar with amphibians, though bullfrogs are distinctly larger. American toads are small, bumpy-skinned toads lacking the smooth skin and prominent tympanum of bullfrogs. Green frogs are significantly smaller than bullfrogs, typically only four to four and a half inches long, with a slender body and a distinctive white stripe down their back. Northern leopard frogs have bold spot patterns and a more streamlined body shape compared to bullfrogs. Pickerel frogs are much smaller with checkered patterns and bright orange coloring on their hindlegs. Spring peepers are tiny, less than an inch and a half long, with characteristic X markings. Gray tree frogs are small climbing frogs with adhesive toe pads and warty skin. Wood frogs have distinctive dark masks across their eyes and are significantly smaller. Mink frogs are small aquatic frogs with a musty odor but lack the large tympanum of bullfrogs. The bullfrog's large size, large prominent tympanum, smooth skin, and useful build make identification straightforward.
Frequently Asked Questions
What does a Minnesota bullfrog sound like? Bullfrogs produce a deep, resonant call resembling jug-o-rum or brrock-brrock, audible from considerable distances during the brief calling season in June and early July. This distinctive sound is the best way to identify bullfrogs. When are bullfrogs most active in Minnesota? Bullfrogs are most active in June and July when calling and breeding occur. They emerge later in spring than southern populations and enter dormancy earlier in autumn. Why are bullfrogs rare in northern Minnesota? Bullfrogs are at the northern edge of their range and require warm water for reproduction. Northern Minnesota's shorter summer and colder water limit bullfrog populations significantly. Are bullfrogs native to Minnesota? Yes, bullfrogs are native to the eastern United States and occur naturally in Minnesota's southern and central regions. How long do Minnesota bullfrogs live? In the wild, bullfrogs typically live five to ten years. Winters in Minnesota are challenging, and not all bullfrogs survive the long hibernation period each year.
More places to see bullfrog
More wildlife in Minnesota