Are There Bullfrogs in Washington?
Yes, bullfrogs are present in Washington but are not native. These large frogs were introduced decades ago and are now well established throughout western Washington and in scattered lowland areas. Bullfrogs pose a significant threat to native amphibians in this region. [Learn about Washington wildlife](/wildlife/washington) and the challenges invasive species create.
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 present in Washington but are not native. These large frogs were introduced decades ago and are now well established throughout western Washington and in scattered lowland areas. Bullfrogs pose a significant threat to native amphibians in this region.Learn about Washington wildlifeand the challenges invasive species create.
Where Bullfrogs Are Found in Washington
Bullfrogs are established throughout western Washington, the region west of the Cascade Mountains where climate and water conditions favor them. They occur in ponds, lakes, marshes, and slow-moving streams from the Puget Sound lowlands south through the Willamette Valley. Bullfrogs are absent or rare east of the Cascades due to cold winters and limited suitable habitat. The Snoqualmie River valley, Lake Union area, and surrounding Puget Sound watersheds support healthy populations. Central Valley lowlands contain numerous bullfrogs. The Skagit River delta and other northern coastal wetlands host populations. Southern Puget Sound wetlands harbor significant numbers. Bullfrogs have established throughout the Columbia River lowlands in southwestern Washington. Their presence is now permanent and widespread in western Washington's major aquatic systems. TheWashington bullfrog guideprovides information on specific locations where bullfrogs concentrate. Seethe Bullfrog guide for Washingtonfor more.
Season and Activity Timing
Washington's mild coastal climate supports bullfrog activity for an extended season compared to colder regions. The active season typically begins in April as water temperatures warm and continues through October. Peak calling activity occurs during June and July when breeding intensifies. Males establish territories and call nightly during this period. Activity levels remain high through August and September but decline as temperatures drop in fall. Some activity may occur into October during warm years. Winter dormancy lasts from November through March, with bullfrogs remaining largely inactive on the bottom of ponds and lakes. Spring warming in April reactivates populations. Rainy periods throughout spring and summer can trigger calling and movement. Overcast, humid evenings produce the most active choruses. MonitoringWashington wildlifefrom April through September provides opportunities to hear and observe bullfrogs.
How to Identify a Bullfrog
Bullfrogs are large, useful frogs reaching 3 to 5 inches in body length and occasionally larger. They have broad heads with distinctly large tympana, the round eardrums visible on the sides of the head. Body coloration ranges from green to brown with darker markings and mottling. Unlike native Washington frogs, bullfrogs lack prominent ridges behind the eyes. Their skin is relatively smooth and moist. Males are smaller than females and develop notably larger tympana. The distinctive call is a deep, resonant "jug o rum" sound repeated in rhythmic sequences. This characteristic call is diagnostic and immediately identifies bullfrogs. Large tadpoles are greenish and reach 2 to 3 inches before metamorphosis. Bullfrogs are easily distinguished from Washington's native frogs by their size and distinctive call.
Where Sightings Concentrate
Bullfrogs concentrate in permanent water bodies with abundant aquatic and emergent vegetation. The Puget Sound lowlands contain the highest densities, particularly in wetland complexes. Ponds with cattails, water lilies, sedges, and other marsh plants provide ideal habitat. Lake margins with shallow vegetation attract bullfrogs. The Snoqualmie River valley and connecting wetlands support significant populations. Beaver ponds and constructed wetlands host bullfrogs when vegetation is present. Agricultural ponds throughout western Washington regularly contain bullfrogs. Retention basins and stormwater ponds in urban areas often support populations. Slow-moving stream reaches with deep pools provide suitable habitat. The Columbia River floodplain wetlands contain numerous bullfrogs. TheWashington wildlife hubidentifies public lands where bullfrogs occur.
Typical Behavior and Diet
Bullfrogs are ambush predators that remain relatively stationary in water, lunging at passing prey. They consume insects, spiders, crustaceans, small fish, other frogs, and occasionally small snakes. Larger bullfrogs readily prey on Washington's native frogs including Pacific tree frogs and red-legged frogs. Bullfrogs are primarily nocturnal hunters but will feed during the day in shaded conditions. Males defend territories and call to attract females and warn rival males. The distinctive territorial call is most intense during June and July. Bullfrogs spend nearly all their time in water, leaving it mainly to migrate to new water bodies or escape threats. Powerful hind legs enable efficient swimming and rapid movement. In Washington's relatively mild winters, bullfrogs remain dormant but may have some winter activity. Their aggressive predatory behavior makes them particularly destructive to native amphibian communities.
Coexistence and Safety Notes
Bullfrogs pose no direct danger to humans and do not bite or attack people. However, bullfrogs are considered a serious invasive species in Washington due to their devastating impact on native amphibians. State wildlife agencies have documented that bullfrog predation significantly reduces populations of red-legged frogs, Oregon spotted frogs, and Pacific tree frogs. They compete with native species for food and habitat. Bullfrogs are not protected under Washington law and can be legally removed. You can safely observe bullfrogs at night using a flashlight. Respectful observation is encouraged. Never intentionally release bullfrogs to new water bodies, as this worsens the invasive problem. Some state agencies offer guidance on controlling bullfrogs.Visit the Washington wildlife hubfor information on invasive species management and conservation efforts.
Species Confusion
The Pacific tree frog is much smaller than a bullfrog, reaching only 1 to 2 inches in length. It makes a loud "croak croak" call rather than the bullfrog's deep "jug o rum." The Oregon spotted frog is smaller with prominent red coloration on the belly. The red-legged frog is smaller and has red coloration on the underside and legs. The rough-skinned newt is smaller with an orange belly and warty skin texture. The tailed frog is tiny and has a unique tail-like extension. The cascade frog is smaller with a different body shape. The foothill yellow-legged frog is smaller and makes different sounds. Learning the bullfrog's deep call is the most reliable identification method. Size alone typically distinguishes bullfrogs from all other Washington native amphibians. Visual confusion is minimal if you understand native species.
Frequently Asked Questions
**Are bullfrogs native to Washington?** No, bullfrogs are not native and are considered an invasive species that threatens native frogs. **How did bullfrogs get to Washington?** Bullfrogs were intentionally introduced to the region decades ago from eastern North America. **Why are bullfrogs harmful in Washington?** They prey heavily on native frogs and reduce populations of red-legged frogs and other species. **When do bullfrogs call in Washington?** Peak calling occurs in June and July during warm, humid evenings. **Where are bullfrogs most common in Washington?** They are well established throughout western Washington, particularly in Puget Sound lowlands. **Can bullfrogs be removed in Washington?** Yes, bullfrogs are not protected and can be legally removed to help native species. **What should you do if you find a bullfrog in Washington?** Report sightings to state wildlife and consider capturing and removing them if you have proper authority. **How do you tell a bullfrog from a native Washington frog?** Bullfrogs are larger and make a deep "jug o rum" call unlike native species calls.
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