Common Garter Snake
Thamnophis sirtalis (Linnaeus, 1758)
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Reptilia
- Order
- Squamata
- Family
- Colubridae
- Genus
- Thamnophis
Conservation status
- Endangered under the US Endangered Species Act (listed as Thamnophis sirtalis tetrataenia) (US Fish and Wildlife Service, list as of November 2026)
Exact locations of listed species are never shown.
Species of concern in Ohio (as Thamnophis sirtalis sirtalis) (Ohio Division of Wildlife, June 2026)
Ohio's Division of Wildlife names it as one that might become threatened in Ohio under continued or increased stress, or one it has some concern for but too little information to judge. It is not listed as endangered or threatened.
Range
Where it is recorded
Season shown in 2 of Ohio's 88 counties. Explore Ohio
Within its mapped range in Ohio. Range: USGS Gap Analysis Project, Species Range Maps CONUS_2001 (2018).
- No result yet (67)
- Recorded, too few records for a result (0)
- Recorded, season not shown (19)
- Season shown (2)
Counties as a table
| County | Records |
|---|---|
| Adams County | No qualifying records yet |
| Allen County | 20 · Recorded, season not shown |
| Ashland County | No qualifying records yet |
| Ashtabula County | 22 · Recorded, season not shown |
| Athens County | 37 · Recorded, season not shown |
| Auglaize County | No qualifying records yet |
| Belmont County | No qualifying records yet |
| Brown County | No qualifying records yet |
| Butler County | No qualifying records yet |
| Carroll County | No qualifying records yet |
| Champaign County | No qualifying records yet |
| Clark County | No qualifying records yet |
| Clermont County | 27 · Recorded, season not shown |
| Clinton County | No qualifying records yet |
| Columbiana County | No qualifying records yet |
| Coshocton County | No qualifying records yet |
| Crawford County | No qualifying records yet |
| Cuyahoga County | 126 · Recorded, season not shown |
| Darke County | No qualifying records yet |
| Defiance County | No qualifying records yet |
| Delaware County | 35 · Recorded, season not shown |
| Erie County | 24 · Recorded, season not shown |
| Fairfield County | No qualifying records yet |
| Fayette County | No qualifying records yet |
| Franklin County | 88 · Recorded, season not shown |
| Fulton County | No qualifying records yet |
| Gallia County | No qualifying records yet |
| Geauga County | 22 · Recorded, season not shown |
| Greene County | 37 · Recorded, season not shown |
| Guernsey County | No qualifying records yet |
| Hamilton County | 65 · Recorded, season not shown |
| Hancock County | 21 · Recorded, season not shown |
| Hardin County | No qualifying records yet |
| Harrison County | No qualifying records yet |
| Henry County | No qualifying records yet |
| Highland County | No qualifying records yet |
| Hocking County | No qualifying records yet |
| Holmes County | No qualifying records yet |
| Huron County | No qualifying records yet |
| Jackson County | No qualifying records yet |
| Jefferson County | No qualifying records yet |
| Knox County | No qualifying records yet |
| Lake County | 67 · Recorded, season not shown |
| Lawrence County | No qualifying records yet |
| Licking County | No qualifying records yet |
| Logan County | No qualifying records yet |
| Lorain County | 40 · Recorded, season not shown |
| Lucas County | 202 · Recorded, season not shown |
| Madison County | No qualifying records yet |
| Mahoning County | No qualifying records yet |
| Marion County | No qualifying records yet |
| Medina County | 40 · Recorded, season not shown |
| Meigs County | No qualifying records yet |
| Mercer County | No qualifying records yet |
| Miami County | No qualifying records yet |
| Monroe County | No qualifying records yet |
| Montgomery County | 30 · Recorded, season not shown |
| Morgan County | No qualifying records yet |
| Morrow County | No qualifying records yet |
| Muskingum County | No qualifying records yet |
| Noble County | No qualifying records yet |
| Ottawa County | 51 · Recorded, season not shown |
| Paulding County | No qualifying records yet |
| Perry County | No qualifying records yet |
| Pickaway County | No qualifying records yet |
| Pike County | No qualifying records yet |
| Portage County | 71 · Recorded, season not shown |
| Preble County | No qualifying records yet |
| Putnam County | No qualifying records yet |
| Richland County | No qualifying records yet |
| Ross County | No qualifying records yet |
| Sandusky County | No qualifying records yet |
| Scioto County | No qualifying records yet |
| Seneca County | No qualifying records yet |
| Shelby County | No qualifying records yet |
| Stark County | 72 · Season shown |
| Summit County | 567 · Season shown |
| Trumbull County | No qualifying records yet |
| Tuscarawas County | No qualifying records yet |
| Union County | No qualifying records yet |
| Van Wert County | No qualifying records yet |
| Vinton County | No qualifying records yet |
| Warren County | No qualifying records yet |
| Washington County | No qualifying records yet |
| Wayne County | No qualifying records yet |
| Williams County | No qualifying records yet |
| Wood County | No qualifying records yet |
| Wyandot County | No qualifying records yet |
Season
When it is recorded
In Ohio
Late March to mid-October, middle week Jun 7–13
Records per week from 5,184 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not how common it is. The grey bars show how many records of all species were made here each week, so you can see when recording itself was high or low; the season is not adjusted by them.
Show as a table
| Week | Records of Common Garter Snake | Years recorded | Records of all species |
|---|---|---|---|
| Jan 4–10 | 1 | 1 | 6,211 |
| Jan 11–17 | 0 | 0 | 5,146 |
| Jan 18–24 | 0 | 0 | 4,645 |
| Jan 25–31 | 1 | 1 | 4,698 |
| Feb 1–7 | 5 | 3 | 6,023 |
| Feb 8–14 | 1 | 1 | 5,888 |
| Feb 15–21 | 1 | 1 | 5,436 |
| Feb 22–28 | 14 | 7 | 6,846 |
| Mar 1–7 | 15 | 4 | 8,321 |
| Mar 8–14 | 31 | 8 | 10,384 |
| Mar 15–21 | 74 | 7 | 12,620 |
| Mar 22–28 | 72 | 9 | 13,949 |
| Mar 29 – Apr 4 | 94 | 9 | 19,661 |
| Apr 5–11 | 164 | 9 | 26,860 |
| Apr 12–18 | 228 | 10 | 39,925 |
| Apr 19–25 | 205 | 10 | 41,623 |
| Apr 26 – May 2 | 227 | 10 | 56,391 |
| May 3–9 | 262 | 10 | 52,952 |
| May 10–16 | 319 | 10 | 53,785 |
| May 17–23 | 328 | 10 | 57,698 |
| May 24–30 | 242 | 10 | 54,651 |
| May 31 – Jun 6 | 211 | 10 | 53,099 |
| Jun 7–13 | 221 | 10 | 53,700 |
| Jun 14–20 | 207 | 10 | 56,625 |
| Jun 21–27 | 143 | 10 | 55,361 |
| Jun 28 – Jul 4 | 143 | 10 | 58,477 |
| Jul 5–11 | 162 | 10 | 61,336 |
| Jul 12–18 | 112 | 9 | 64,722 |
| Jul 19–25 | 120 | 8 | 69,753 |
| Jul 26 – Aug 1 | 115 | 9 | 59,416 |
| Aug 2–8 | 85 | 10 | 59,712 |
| Aug 9–15 | 99 | 10 | 55,994 |
| Aug 16–22 | 115 | 10 | 54,328 |
| Aug 23–29 | 100 | 10 | 51,772 |
| Aug 30 – Sep 5 | 145 | 10 | 57,167 |
| Sep 6–12 | 107 | 10 | 59,075 |
| Sep 13–19 | 142 | 10 | 54,543 |
| Sep 20–26 | 132 | 10 | 45,860 |
| Sep 27 – Oct 3 | 91 | 10 | 43,180 |
| Oct 4–10 | 96 | 10 | 37,841 |
| Oct 11–17 | 97 | 10 | 30,824 |
| Oct 18–24 | 66 | 10 | 21,156 |
| Oct 25–31 | 74 | 10 | 19,021 |
| Nov 1–7 | 32 | 9 | 14,172 |
| Nov 8–14 | 48 | 7 | 12,621 |
| Nov 15–21 | 11 | 6 | 7,965 |
| Nov 22–28 | 12 | 6 | 8,136 |
| Nov 29 – Dec 5 | 4 | 4 | 6,083 |
| Dec 6–12 | 2 | 1 | 6,004 |
| Dec 13–19 | 0 | 0 | 5,423 |
| Dec 20–26 | 3 | 3 | 5,661 |
| Dec 27 – Jan 2 | 5 | 4 | 8,459 |
What these results show
These results show when people recorded a species, not when or where it occurs. Missing weeks and low counts do not mean absence or scarcity, and counts are not abundance. Contributed records reflect where, when and what people chose to observe.
Relatives
In the same genus
Other Thamnophis recorded in Ohio
Identification
How to identify it
Often confused with
- DeKay's Brownsnake Storeria dekayiOften confused in Ohio: 158 identifications in Ohio named one where the other was meant
- Common Ribbon Snake Thamnophis sauritaOften confused in Ohio: 87 identifications in Ohio named one where the other was meant
- Butler's Garter Snake Thamnophis butleriOften confused in Ohio: 57 identifications in Ohio named one where the other was meant
- North American Racer Coluber constrictorOften confused in Ohio: 36 identifications in Ohio named one where the other was meant
- Common Watersnake Nerodia sipedonOften confused in Ohio: 21 identifications in Ohio named one where the other was meant
From iNaturalist’s similar-species counts, refreshed monthly: confusions in Ohio first, then worldwide. Only species with an Ohio result are listed.
Times of day, land cover and photos from records are not shown for species whose locations are protected.
Finer identifications
Some Ohio records of this species were identified to a subspecies:
- Thamnophis sirtalis sirtalisEastern Garter Snakesubspecies
A few other records were identified to other subspecies.
Every one of these records counts toward the Common Garter Snake's season above.
Why some records go further than species
Many species vary from place to place. Groups of a species that look or sound a little different, and live in different areas, can be named as subspecies. Observers and experts only identify a record that far when it shows enough detail to tell them apart. Records without that detail count at the species level.
Names: Catalogue of Life.
Sources
Where these results come from
- Records from iNaturalist research-grade observations and expert-identified GBIF datasets, CC0, CC BY and CC BY-NC. Sources
- Seasons use the published method and its evidence thresholds. Methods
- See it on iNaturalist (opens in a new tab)OpenPhenology is independent and not affiliated with iNaturalist.
Records behind the Ohio result
5,184 records from 3 datasets.
- iNaturalist Research-grade Observations (opens in a new tab) · iNaturalist.org · 5,141 recordsiNaturalist contributors, iNaturalist (2026). iNaturalist Research-grade Observations. iNaturalist.org. Occurrence dataset https://doi.org/10.15468/ab3s5x accessed via GBIF.org on 2026-11-13.
- iNaturalist observations (opens in a new tab) · iNaturalist.org · 42 recordsiNaturalist. Available from https://www.inaturalist.org. Accessed 2026-11-13
- University of Florida Herpetology (opens in a new tab) · Florida Museum of Natural History · 1 recordBlackburn D, Brown W (2026). University of Florida Herpetology. Florida Museum of Natural History. Occurrence dataset https://doi.org/10.15468/vw3dvj accessed via GBIF.org on 2026-11-13.
To cite: the GBIF downloads doi:10.15468/dl.8m7c3d (opens in a new tab), doi:10.15468/dl.y2jkt8 (opens in a new tab).
Links to individual records are not shown for this species, to protect the places it is recorded.