22 Types of Frogs in Illinois
Illinois hosts over 15 frog species, from the common American bullfrog to the secretive eastern spadefoot. Most are found near water in spring and summer. Start your search in wetlands, ponds, and slow streams, especially after rain. Listen for calls: each species has a distinct sound.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 6, 2026.
Verified species, source iNaturalist
22 types of frogs recorded in Illinois
22 frog species have a verified observation record in Illinois, each with at least 10 confirmed sightings. The full list, ranked by how often each is recorded, is below.
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Also recorded in Illinois
| # | Species | Scientific name | Records |
|---|---|---|---|
| 13 | Bird-voiced TreefrogDryophytes avivoca | Dryophytes avivoca | 195 |
| 14 | Plains Leopard FrogLithobates blairi | Lithobates blairi | 180 |
| 15 | Wood FrogLithobates sylvaticus | Lithobates sylvaticus | 156 |
| 16 | Western Chorus FrogPseudacris triseriata | Pseudacris triseriata | 102 |
| 17 | Pickerel FrogLithobates palustris | Lithobates palustris | 74 |
| 18 | Crawfish FrogLithobates areolatus | Lithobates areolatus | 43 |
| 19 | Eastern Narrow-mouthed ToadGastrophryne carolinensis | Gastrophryne carolinensis | 32 |
| 20 | Illinois Chorus FrogPseudacris illinoensis | Pseudacris illinoensis | 26 |
| 21 | Eastern SpadefootScaphiopus holbrookii | Scaphiopus holbrookii | 24 |
| 22 | Upland Chorus FrogPseudacris feriarum | Pseudacris feriarum | 14 |
Plus 3 more recorded only rarely (fewer than 10 verified sightings). Counts from verified iNaturalist observations. Photos by iNaturalist observers, reused under the licence each observer chose.
Illinois hosts over 15 frog species, from the common American bullfrog to the secretive eastern spadefoot. Most are found near water in spring and summer. Start your search in wetlands, ponds, and slow streams, especially after rain. Listen for calls: each species has a distinct sound.
1. What are the most useful ID markers for Illinois frogs?
Focus on size, dorsal ridges, and toe pads. For example, the American bullfrog lacks dorsolateral ridges, while the green frog has them. Look for webbing: northern leopard frogs have extensive webbing. Color varies, but pattern (spots, stripes) is reliable. Call is the best clue: listen for the banjo-like 'jug-o-rum' of bullfrogs or the snoring of leopard frogs. Seeour frog identification guidefor side-by-side comparisons.
In Illinois, frogs sightings usually improve when you slow down and match your first stop to the most useful ID markers and likely lookalikes. Use thestate wildlife huband theroute guideto narrow your first area, then check access, weather, and distance before you settle in. A short walk with one clear viewing plan often beats covering too much ground, especially when habitat changes fast from open edges to brush, wetlands, timber, shoreline, or neighborhood cover.
2. Where in Illinois do people usually notice frogs first?
Frogs are most often seen in southern Illinois, especially the Shawnee National Forest and the Cache River Wetlands. Northern areas like the Chain O'Lakes and Volo Bog are good for pickerel frogs and gray tree frogs. Start near shallow, vegetated water bodies. In central Illinois, the Emiquon Preserve and wetland restorations are reliable. CheckIllinois wildlife hotspotsfor specific locations.
3. What is the best season or time window for confident sightings?
March through July is peak frog activity in Illinois. Early spring (March-April) is best for chorus frogs and spring peepers. Late spring (May-June) brings bullfrogs and green frogs. Nighttime after rain is ideal: use a flashlight and listen for calls. Early morning works too. Colder months: few frogs are active; you might find spring peepers on warm winter days. Timing matters more than luck.
See ourstate animal guidefor the next step.
4. How can you tell lookalike species apart?
The green frog and bullfrog are often confused. Check dorsolateral ridges: green frogs have them, bullfrogs do not. Leopard frogs and pickerel frogs: leopard frogs have round spots, pickerel frogs have square-ish ones in two rows. Gray tree frogs and Cope's gray tree frogs are nearly identical; call is the only reliable difference. Use a field guide orour frog species breakdownto avoid mix-ups.
5. What are the most common frogs in Illinois?
The American bullfrog, green frog, northern leopard frog, gray tree frog, and spring peeper are widespread. In southern Illinois, you may also find the bird-voiced tree frog and the Illinois chorus frog. The crawfish frog is rare but present in wet prairies. Each has a unique call: spring peepers sound like sleigh bells, bullfrogs like a low drum.
6. Are there any rare or special frog species to look for?
Yes. The eastern spadefoot toad (actually a frog) is secretive and only appears after heavy rain. The Illinois chorus frog is a state-threatened species found in scattered wetlands. The bird-voiced tree frog reaches its northern limit in Illinois. These species require careful timing and specific habitat. CheckIllinois rare species listsfor details.
7. What frog-themed prints work well for a field reference or display?
After a day of spotting, bring the experience home. The **Red Eyed Tree Frog Limited-Edition Print** captures the iconic look of a tropical species, but Illinois tree frogs share similar toe pads. The **Pine Barrens Tree Frog Limited-Edition Print** shows a species found in the East, good for comparison. Both prints are detailed enough for ID study.Check the Red Eyed Tree Frog Printandthe Pine Barrens Print. For a broader collection, browseour wildlife art prints(including t-shirts).
Wall art print: Frog by Eimear Maguire on Artfully Walls. Illustration, Animals, framed or unframed art printed on fine art paper
Product from otherCheck Price and Availability
8. Frequently asked questions about Illinois frog identification
**How do I distinguish a bullfrog from a green frog?** Look for dorsolateral ridges: green frogs have them, bullfrogs don't. **What time of day are frogs most active?** Night, especially after rain. **Can I record frog calls?** Yes, use a phone app; recording helps ID later. **Where can I find a field guide?** Start withour frog pageandIllinois wildlife resources.
See ourtour planning ideasfor the next step.
Gear and field guides
Frequently asked questions
1. What are the most useful ID markers for Illinois frogs?+
Focus on size, dorsal ridges, and toe pads. For example, the American bullfrog lacks dorsolateral ridges, while the green frog has them. Look for webbing: northern leopard frogs have extensive webbing. Color varies, but pattern (spots, stripes) is reliable. Call is the best clue: listen for the banjo-like 'jug-o-rum' of bullfrogs or the snoring of leopard frogs. Seeour frog identification guidefor side-by-side comparisons. In Illinois, frogs sightings usually improve when you slow down and match your first stop to the most useful ID markers and likely lookalikes. Use thestate wildlife huband theroute guideto narrow your first area, then check access, weather, and distance before you settle in. A short walk with one clear viewing plan often beats covering too much ground, especially when habitat changes fast from open edges to brush, wetlands, timber, shoreline, or neighborhood cover.
2. Where in Illinois do people usually notice frogs first?+
Frogs are most often seen in southern Illinois, especially the Shawnee National Forest and the Cache River Wetlands. Northern areas like the Chain O'Lakes and Volo Bog are good for pickerel frogs and gray tree frogs. Start near shallow, vegetated water bodies. In central Illinois, the Emiquon Preserve and wetland restorations are reliable. CheckIllinois wildlife hotspotsfor specific locations.
3. What is the best season or time window for confident sightings?+
March through July is peak frog activity in Illinois. Early spring (March-April) is best for chorus frogs and spring peepers. Late spring (May-June) brings bullfrogs and green frogs. Nighttime after rain is ideal: use a flashlight and listen for calls. Early morning works too. Colder months: few frogs are active; you might find spring peepers on warm winter days. Timing matters more than luck. See ourstate animal guidefor the next step.
4. How can you tell lookalike species apart?+
The green frog and bullfrog are often confused. Check dorsolateral ridges: green frogs have them, bullfrogs do not. Leopard frogs and pickerel frogs: leopard frogs have round spots, pickerel frogs have square-ish ones in two rows. Gray tree frogs and Cope's gray tree frogs are nearly identical; call is the only reliable difference. Use a field guide orour frog species breakdownto avoid mix-ups.
5. What are the most common frogs in Illinois?+
The American bullfrog, green frog, northern leopard frog, gray tree frog, and spring peeper are widespread. In southern Illinois, you may also find the bird-voiced tree frog and the Illinois chorus frog. The crawfish frog is rare but present in wet prairies. Each has a unique call: spring peepers sound like sleigh bells, bullfrogs like a low drum.
6. Are there any rare or special frog species to look for?+
Yes. The eastern spadefoot toad (actually a frog) is secretive and only appears after heavy rain. The Illinois chorus frog is a state-threatened species found in scattered wetlands. The bird-voiced tree frog reaches its northern limit in Illinois. These species require careful timing and specific habitat. CheckIllinois rare species listsfor details.
7. What frog-themed prints work well for a field reference or display?+
After a day of spotting, bring the experience home. The **Red Eyed Tree Frog Limited-Edition Print** captures the iconic look of a tropical species, but Illinois tree frogs share similar toe pads. The **Pine Barrens Tree Frog Limited-Edition Print** shows a species found in the East, good for comparison. Both prints are detailed enough for ID study.Check the Red Eyed Tree Frog Printandthe Pine Barrens Print. For a broader collection, browseour wildlife art prints(including t-shirts). ### Wall art print: Frog by Eimear Maguire on Artfully Walls. Illustration, Animals, framed or unframed art printed on fine art paper Product from otherCheck Price and Availability
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