Maps
Locality Map

Locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
County Map

County map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Historical Locality Map

Historical locality map for Crotalus horridus (Timber Rattlesnake). Black circles (
) represent records after 1986, blue squares (
) represent records between 1966 and 1986, orange triangles (
) represent records prior to 1966. Note that more recent records might conceal underlying older records.
Map created 6 March 2024.
Historical County Map

Historical county map for Crotalus horridus (Timber Rattlesnake). Black circles (
) represent records after 1986, blue squares (
) represent records between 1966 and 1986, orange triangles (
) represent records prior to 1966. Note that only the most recent county record for each county is shown.
Map created 6 March 2024.
Ecological Drainage Locality Map

Ecological Drainage Units locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Natural Divisions Locality Map

Natural Divisions and Sections locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Major Watersheds Locality Map

Major Watersheds locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Level I Ecoregion Locality Map

Level I Ecoregion locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Level II Ecoregion Locality Map

Level II Ecoregion locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Level III Ecoregion Locality Map

Level III Ecoregion locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Level IV Ecoregion Locality Map

Level IV Ecoregion locality map for Crotalus horridus (Timber Rattlesnake).
Map created 6 March 2024.
Native Status
Crotalus horridus (Timber Rattlesnake) is native to Missouri.
Collection Summary
Crotalus horridus (Timber Rattlesnake) has a total of 380 valid, non-duplicated collections representing 75 counties and 208 localities. There are a total of 101 collectors and 169 collection dates for the species. This results in a total of 180 expeditions for the species, a measure of unique date / collector(s) combinations. The earliest collection year for the species in Missouri is 1898 and its most recent collection year is 2023. The earliest and latest collection dates (independent of earliest and most recent collection years) are February 14 and November 20, respectively. If you have a new record to report, read the New Records section of the FAQ.
Collection Summary by County
| County | Localities | Collections | Collectors | Dates | Expeditions | Earliest Year | Latest Year | |
|---|---|---|---|---|---|---|---|---|
![]() | Adair | 1 | 2 | 2 | 2 | 2 | 1959 | 1965 |
![]() | Andrew | 1 | 1 | 2 | 1 | 1 | 1992 | 1992 |
![]() | Barry | 1 | 1 | 1 | 1 | 1 | 2003 | 2003 |
![]() | Barton | 1 | 2 | 1 | 2 | 2 | 1900 | 1900 |
![]() | Bates | 2 | 4 | 1 | 2 | 2 | 1958 | 1958 |
![]() | Benton | 1 | 1 | 1 | 1 | 1 | 2015 | 2015 |
![]() | Bollinger | 1 | 1 | 1 | 1 | 1 | ||
![]() | Boone | 13 | 15 | 12 | 13 | 14 | 1934 | 2014 |
![]() | Buchanan | 1 | 1 | 1 | 1 | 1 | ||
![]() | Butler | 1 | 1 | 3 | 1 | 1 | 2007 | 2007 |
![]() | Caldwell | 3 | 10 | 1 | 3 | 3 | 1954 | 1954 |
![]() | Callaway | 2 | 2 | 2 | 2 | 2 | 1999 | 1999 |
![]() | Cape Girardeau | 3 | 3 | 3 | 2 | 3 | 1972 | 1995 |
![]() | Carroll | 1 | 2 | 1 | 2 | 2 | 1961 | 1961 |
![]() | Carter | 1 | 2 | 3 | 2 | 2 | 1931 | 1931 |
![]() | Cass | 1 | 3 | 1 | 2 | 2 | 1942 | 1942 |
![]() | Chariton | 1 | 1 | 1 | 1 | 1 | 1940 | 1940 |
![]() | Christian | 4 | 4 | 1 | 3 | 3 | 2011 | 2013 |
![]() | Clark | 1 | 1 | 1 | 1 | 1 | ||
![]() | Clay | 5 | 10 | 2 | 4 | 4 | 1939 | 1958 |
![]() | Clinton | 1 | 1 | 1 | 1 | 1 | ||
![]() | Cooper | 1 | 1 | 1 | 1 | 1 | 2017 | 2017 |
![]() | Dade | 1 | 1 | 1 | 1 | 1 | 2018 | 2018 |
![]() | Dallas | 1 | 1 | 1 | 1 | 1 | 2007 | 2007 |
![]() | Daviess | 2 | 2 | 4 | 2 | 2 | 2014 | 2014 |
![]() | Dent | 1 | 1 | 2 | 1 | 1 | 1997 | 1997 |
![]() | Dunklin | 1 | 1 | 1 | 1 | 1 | 1900 | 1900 |
![]() | Gentry | 4 | 4 | 2 | 4 | 4 | 2000 | 2003 |
![]() | Grundy | 5 | 6 | 3 | 3 | 3 | 1964 | 2006 |
![]() | Harrison | 1 | 1 | 1 | 1 | 1 | 2006 | 2006 |
![]() | Henry | 2 | 2 | 1 | 1 | 1 | ||
![]() | Hickory | 1 | 1 | 1 | 1 | 1 | 2005 | 2005 |
![]() | Holt | 9 | 13 | 3 | 9 | 10 | 1959 | 1974 |
![]() | Howard | 1 | 1 | 1 | 1 | 1 | ||
![]() | Howell | 1 | 1 | 1 | 1 | 1 | 1909 | 1909 |
![]() | Iron | 3 | 3 | 3 | 3 | 3 | 2009 | 2023 |
![]() | Jackson | 30 | 82 | 6 | 32 | 32 | 1929 | 2003 |
![]() | Jefferson | 4 | 6 | 3 | 3 | 3 | 1898 | 2009 |
![]() | Johnson | 6 | 9 | 3 | 6 | 6 | 1909 | 1991 |
![]() | Laclede | 1 | 1 | 1 | 1 | 1 | 2002 | 2002 |
![]() | Lafayette | 1 | 2 | 1 | 2 | 2 | 1939 | 1939 |
![]() | Lincoln | 1 | 1 | 1 | 1 | 1 | 2016 | 2016 |
![]() | Livingston | 2 | 2 | 2 | 2 | 2 | 1940 | 2020 |
![]() | Madison | 1 | 2 | 5 | 1 | 2 | 2007 | 2007 |
![]() | McDonald | 2 | 2 | 2 | 2 | 2 | 2021 | 2021 |
![]() | Mercer | 1 | 1 | 2 | 1 | 1 | 2018 | 2018 |
![]() | Moniteau | 1 | 1 | 1 | 1 | 1 | 2012 | 2012 |
![]() | Monroe | 2 | 2 | 4 | 2 | 2 | 2001 | 2017 |
![]() | Montgomery | 3 | 3 | 4 | 3 | 3 | 1995 | 2015 |
![]() | Morgan | 1 | 1 | 1 | 1 | 1 | 1948 | 1948 |
![]() | Osage | 2 | 2 | 2 | 2 | 2 | 1996 | 2006 |
![]() | Perry | 1 | 1 | 4 | 1 | 1 | 2008 | 2008 |
![]() | Pettis | 7 | 11 | 5 | 7 | 8 | 1939 | 1976 |
![]() | Pike | 6 | 18 | 2 | 4 | 5 | 1938 | 1939 |
![]() | Platte | 5 | 7 | 1 | 2 | 2 | 1948 | 1948 |
![]() | Ralls | 2 | 2 | 2 | 2 | 2 | 1979 | 2012 |
![]() | Ray | 5 | 59 | 5 | 9 | 9 | 1951 | 2020 |
![]() | Reynolds | 1 | 1 | 2 | 1 | 1 | 2008 | 2008 |
![]() | Ripley | 1 | 1 | 2 | 1 | 1 | 2013 | 2013 |
![]() | Saint Charles | 1 | 1 | 1 | 1 | 1 | 2003 | 2003 |
![]() | Saint Clair | 1 | 1 | 1 | 1 | 1 | 2005 | 2005 |
![]() | Sainte Genevieve | 1 | 1 | 1 | 1 | 1 | 1902 | 1902 |
![]() | Saint Francois | 1 | 1 | 1 | 1 | 1 | 2019 | 2019 |
![]() | Saint Louis | 7 | 8 | 4 | 3 | 5 | 1907 | 2009 |
![]() | Saline | 2 | 3 | 1 | 2 | 2 | 1940 | 1940 |
![]() | Schuyler | 1 | 1 | 1 | 1 | 1 | 2009 | 2009 |
![]() | Scott | 2 | 4 | 1 | 2 | 2 | 1985 | 1985 |
![]() | Shannon | 3 | 3 | 3 | 3 | 3 | 1992 | 2011 |
![]() | Stoddard | 3 | 11 | 4 | 8 | 8 | 1935 | 1969 |
![]() | Stone | 2 | 3 | 2 | 2 | 2 | 1908 | 1908 |
![]() | Sullivan | 3 | 3 | 3 | 3 | 3 | 2008 | 2012 |
![]() | Taney | 1 | 1 | 1 | 1 | 1 | 2000 | 2000 |
![]() | Warren | 2 | 2 | 2 | 2 | 2 | 1993 | 2020 |
![]() | Washington | 2 | 2 | 2 | 2 | 2 | 2003 | 2003 |
![]() | Wayne | 8 | 9 | 11 | 7 | 7 | 1956 | 2015 |
Potential County Records
| Likelihood | County | Rationale | Ecoregion / Watershed | |
|---|---|---|---|---|
![]() | 2 | Audrain | Same Level IV ecoregion, within 5 miles | Claypan Prairie |
![]() | 2 | Camden | Same Level IV ecoregion, within 5 miles | Osage/Gasconade Hills |
![]() | 2 | Cole | Same Level IV ecoregion, within 5 miles | River Hills |
![]() | 2 | Crawford | Same Level IV ecoregion, within 5 miles | Meramec River Hills |
![]() | 2 | De Kalb | Same Level IV ecoregion, within 5 miles | Loess Flats and Till Plains |
![]() | 2 | Franklin | Same Level IV ecoregion, within 5 miles | River Hills |
![]() | 2 | Franklin | Same Level IV ecoregion, within 5 miles | Eastern Ozark Border |
![]() | 2 | Gasconade | Same Level IV ecoregion, within 5 miles | River Hills |
![]() | 2 | Linn | Same Level IV ecoregion, within 5 miles | Loess Flats and Till Plains |
![]() | 2 | Maries | Same Level IV ecoregion, within 5 miles | Central Plateau |
![]() | 2 | Miller | Same Level IV ecoregion, within 5 miles | Osage/Gasconade Hills |
![]() | 2 | Putnam | Same Level IV ecoregion, within 5 miles | Loess Flats and Till Plains |
![]() | 4 | Atchison | Same Level IV ecoregion, within 10 miles | Missouri Alluvial Plain |
![]() | 4 | Cedar | Same Level IV ecoregion, within 10 miles | Springfield Plateau |
![]() | 4 | Greene | Same Level IV ecoregion, within 10 miles | Springfield Plateau |
![]() | 4 | Lewis | Same Level IV ecoregion, within 10 miles | Loess Flats and Till Plains |
![]() | 4 | Macon | Same Level IV ecoregion, within 10 miles | Loess Flats and Till Plains |
![]() | 4 | Marion | Same Level IV ecoregion, within 10 miles | River Hills |
![]() | 4 | Newton | Same Level IV ecoregion, within 10 miles | Dissected Springfield Plateau-Elk River Hills |
![]() | 4 | Oregon | Same Level IV ecoregion, within 10 miles | Current River Hills |
![]() | 4 | Phelps | Same Level IV ecoregion, within 10 miles | Meramec River Hills |
![]() | 4 | Texas | Same Level IV ecoregion, within 10 miles | Current River Hills |
![]() | 6 | Douglas | Same Level IV ecoregion, within 20 miles | White River Hills |
![]() | 6 | Jasper | Same Level IV ecoregion, within 20 miles | Springfield Plateau |
![]() | 6 | Knox | Same Level IV ecoregion, within 20 miles | Loess Flats and Till Plains |
![]() | 6 | Knox | Same Level IV ecoregion, within 20 miles | Claypan Prairie |
![]() | 6 | Lawrence | Same Level IV ecoregion, within 20 miles | Springfield Plateau |
![]() | 6 | Nodaway | Same Level IV ecoregion, within 20 miles | Loess Flats and Till Plains |
![]() | 6 | Nodaway | Same Level IV ecoregion, within 20 miles | Rolling Loess Prairies |
![]() | 6 | Ozark | Same Level IV ecoregion, within 20 miles | White River Hills |
![]() | 6 | Polk | Same Level IV ecoregion, within 20 miles | Springfield Plateau |
![]() | 6 | Polk | Same Level IV ecoregion, within 20 miles | Osage/Gasconade Hills |
![]() | 6 | Pulaski | Same Level IV ecoregion, within 20 miles | Central Plateau |
![]() | 6 | Randolph | Same Level IV ecoregion, within 20 miles | River Hills |
![]() | 6 | Randolph | Same Level IV ecoregion, within 20 miles | Claypan Prairie |
![]() | 6 | Scotland | Same Level IV ecoregion, within 20 miles | Loess Flats and Till Plains |
![]() | 6 | Shelby | Same Level IV ecoregion, within 20 miles | River Hills |
![]() | 6 | Webster | Same Level IV ecoregion, within 20 miles | Central Plateau |
![]() | 6 | Webster | Same Level IV ecoregion, within 20 miles | White River Hills |
![]() | 6 | Worth | Same Level IV ecoregion, within 20 miles | Loess Flats and Till Plains |
![]() | 6 | Wright | Same Level IV ecoregion, within 20 miles | Central Plateau |
![]() | 7 | Mississippi | Same Level III ecoregion, within 20 miles | Interior River Valleys and Hills |
![]() | 8 | New Madrid | Same Level IV ecoregion, within 30 miles | St. Francis Lowlands |
![]() | 8 | Vernon | Same Level IV ecoregion, within 30 miles | Wooded Osage Plains |
![]() | 8 | Vernon | Same Level IV ecoregion, within 30 miles | Cherokee Plains |
![]() | 10 | Pemiscot | Same Level IV ecoregion, adjacent county | St. Francis Lowlands |
Linnaean Classification
- Kingdom:
- Animalia - Animals
- Phylum:
- Chordata - Chordates
- Subphylum:
- Vertebrata - Vertebrates
- Class:
- Reptilia Laurenti, 1768 - Reptiles
- Order:
- Squamata Oppel, 1811 - Lizards and Snakes
- Suborder:
- Serpentes Linnaeus, 1758 - Snakes
- Family:
- Viperidae Bonaparte, 1840 - Asps and Vipers
- Genus:
- Crotalus Linnaeus, 1758 - Rattlesnakes
- Species:
- Crotalus horridus Linnaeus, 1758 - Timber Rattlesnake
Recent Taxonomic Synonyms
(none)




