Collection Summary
Pantherophis obsoletus (Western Ratsnake) has a total of 621 valid, non-duplicated collections representing 111 counties and 505 localities. There are a total of 200 collectors and 457 collection dates for the species. This results in a total of 488 expeditions for the species, a measure of unique date / collector(s) combinations. The earliest collection year for the species in Missouri is 1889 and its most recent collection year is 2023. The earliest and latest collection dates (independent of earliest and most recent collection years) are January 4 and November 28, 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 | 3 | 3 | 4 | 3 | 3 | 1939 | 1961 |
| Andrew | 2 | 2 | 2 | 2 | 2 | 1959 | 2017 |
| Atchison | 1 | 1 | 1 | 1 | 1 | 1968 | 1968 |
| Audrain | 3 | 3 | 2 | 3 | 3 | 1939 | 2000 |
| Barry | 4 | 5 | 8 | 5 | 5 | 1937 | 2004 |
| Barton | 7 | 7 | 6 | 7 | 7 | 1987 | 2022 |
| Bates | 3 | 3 | 2 | 3 | 3 | 1958 | 2007 |
| Benton | 3 | 3 | 3 | 3 | 3 | 1958 | 2004 |
| Bollinger | 4 | 5 | 5 | 5 | 5 | 1969 | 2019 |
| Boone | 9 | 14 | 8 | 13 | 14 | 1940 | 2022 |
| Buchanan | 1 | 1 | 1 | 1 | 1 | 1982 | 1982 |
| Butler | 5 | 7 | 6 | 6 | 6 | 1956 | 1995 |
| Caldwell | 3 | 3 | 2 | 3 | 3 | 1954 | 2017 |
| Callaway | 3 | 3 | 1 | 3 | 3 | 1998 | 2023 |
| Camden | 5 | 6 | 4 | 4 | 4 | 1938 | 2006 |
| Cape Girardeau | 7 | 10 | 9 | 8 | 9 | 1923 | 1996 |
| Carroll | 2 | 2 | 2 | 2 | 2 | 1961 | 1983 |
| Carter | 6 | 8 | 9 | 7 | 7 | 1930 | 2002 |
| Cass | 4 | 4 | 3 | 4 | 4 | 1948 | 2014 |
| Cedar | 3 | 3 | 2 | 3 | 3 | 1990 | 2018 |
| Chariton | 7 | 8 | 3 | 7 | 7 | 1999 | 2020 |
| Christian | 1 | 1 | 1 | 1 | 1 | 1967 | 1967 |
| Clark | 2 | 2 | 2 | 2 | 2 | 1979 | 2005 |
| Clay | 3 | 3 | 3 | 3 | 3 | 1939 | 1964 |
| Clinton | 1 | 3 | 1 | 3 | 3 | 1961 | 1961 |
| Cole | 3 | 3 | 3 | 3 | 3 | 1938 | 2006 |
| Cooper | 2 | 2 | 2 | 2 | 2 | 1991 | 2013 |
| Crawford | 4 | 4 | 3 | 4 | 4 | 1934 | 2003 |
| Dade | 5 | 5 | 5 | 5 | 5 | 1983 | 2021 |
| Dallas | 6 | 8 | 8 | 6 | 6 | 2000 | 2019 |
| Daviess | 2 | 2 | 3 | 2 | 2 | 2001 | 2015 |
| De Kalb | 1 | 1 | 1 | 1 | 1 | 2020 | 2020 |
| Dent | 2 | 5 | 6 | 4 | 4 | 1909 | 2013 |
| Douglas | 1 | 1 | 2 | 1 | 1 | 1978 | 1978 |
| Dunklin | 6 | 8 | 6 | 8 | 8 | 1936 | 1995 |
| Franklin | 5 | 9 | 5 | 6 | 6 | 1933 | 1999 |
| Gasconade | 2 | 2 | 2 | 2 | 2 | 1934 | 2007 |
| Gentry | 3 | 4 | 4 | 3 | 3 | 1997 | 2019 |
| Greene | 44 | 55 | 15 | 44 | 44 | 1957 | 2023 |
| Grundy | 9 | 9 | 5 | 6 | 6 | 1964 | 2010 |
| Harrison | 1 | 1 | 1 | 1 | 1 | 1992 | 1992 |
| Henry | 4 | 4 | 11 | 4 | 4 | 1962 | 2007 |
| Hickory | 3 | 3 | 4 | 3 | 3 | 1950 | 2018 |
| Holt | 5 | 6 | 4 | 5 | 5 | 1953 | 2019 |
| Howard | 5 | 5 | 2 | 5 | 5 | 1999 | 2015 |
| Howell | 1 | 1 | 1 | 1 | 1 | 1973 | 1973 |
| Iron | 4 | 4 | 6 | 4 | 4 | 1991 | 2020 |
| Jackson | 23 | 35 | 7 | 26 | 29 | 1932 | 1983 |
| Jasper | 4 | 4 | 3 | 4 | 4 | 1982 | 2018 |
| Jefferson | 11 | 14 | 3 | 6 | 6 | 1900 | 1998 |
| Johnson | 11 | 18 | 12 | 13 | 13 | 1961 | 2008 |
| Knox | 2 | 2 | 2 | 2 | 2 | 1961 | 2012 |
| Laclede | 7 | 7 | 9 | 7 | 7 | 1999 | 2020 |
| Lafayette | 2 | 2 | 4 | 2 | 2 | 1990 | 2014 |
| Lawrence | 5 | 5 | 3 | 5 | 5 | 1994 | 2015 |
| Lewis | 2 | 2 | 2 | 2 | 2 | 1940 | 2013 |
| Lincoln | 4 | 5 | 3 | 4 | 4 | 1963 | 2013 |
| Linn | 3 | 4 | 3 | 4 | 4 | 1980 | 2005 |
| Livingston | 3 | 3 | 3 | 3 | 3 | 1961 | 2020 |
| Macon | 2 | 2 | 2 | 2 | 2 | 1961 | 2023 |
| Madison | 3 | 3 | 5 | 3 | 3 | 1982 | 2020 |
| Maries | 2 | 2 | 3 | 2 | 2 | 2000 | 2001 |
| McDonald | 3 | 4 | 3 | 4 | 4 | 1930 | 2002 |
| Mercer | 1 | 1 | 1 | 1 | 1 | 1983 | 1983 |
| Miller | 3 | 3 | 5 | 3 | 3 | 1973 | 2020 |
| Mississippi | 5 | 5 | 5 | 5 | 5 | 1984 | 2011 |
| Moniteau | 3 | 3 | 2 | 3 | 3 | 1966 | 2015 |
| Monroe | 2 | 2 | 2 | 2 | 2 | 1933 | 2001 |
| Montgomery | 2 | 4 | 4 | 4 | 4 | 1901 | 2018 |
| Morgan | 4 | 4 | 2 | 3 | 3 | 2015 | 2019 |
| New Madrid | 2 | 2 | 4 | 2 | 2 | 1995 | 2008 |
| Newton | 6 | 7 | 8 | 6 | 6 | 1992 | 2002 |
| Nodaway | 7 | 7 | 4 | 5 | 5 | 1966 | 2015 |
| Oregon | 9 | 9 | 6 | 8 | 8 | 1950 | 2017 |
| Osage | 4 | 4 | 3 | 4 | 4 | 1991 | 2010 |
| Ozark | 4 | 4 | 5 | 4 | 4 | 1986 | 2020 |
| Pemiscot | 4 | 5 | 3 | 3 | 4 | 1923 | 1963 |
| Perry | 7 | 8 | 5 | 5 | 7 | 1923 | 2017 |
| Pettis | 6 | 8 | 3 | 5 | 5 | 1939 | 2021 |
| Phelps | 6 | 6 | 7 | 6 | 6 | 2001 | 2022 |
| Pike | 9 | 9 | 8 | 9 | 9 | 1971 | 2013 |
| Platte | 2 | 2 | 1 | 2 | 2 | 1983 | 1983 |
| Polk | 10 | 10 | 5 | 10 | 10 | 1961 | 2023 |
| Pulaski | 1 | 1 | 1 | 1 | 1 | 1957 | 1957 |
| Putnam | 1 | 1 | 1 | 1 | 1 | 2016 | 2016 |
| Ralls | 2 | 2 | 1 | 2 | 2 | 2002 | 2002 |
| Randolph | 5 | 5 | 3 | 5 | 5 | 2000 | 2022 |
| Ray | 2 | 16 | 2 | 7 | 7 | 1951 | 1953 |
| Reynolds | 4 | 4 | 5 | 4 | 4 | 1933 | 2020 |
| Ripley | 2 | 2 | 3 | 2 | 2 | 2001 | 2007 |
| Saint Charles | 7 | 9 | 5 | 8 | 8 | 1958 | 2010 |
| Saint Clair | 5 | 6 | 5 | 6 | 6 | 1931 | 2007 |
| Sainte Genevieve | 3 | 3 | 4 | 2 | 2 | 1988 | 2010 |
| Saint Francois | 3 | 3 | 3 | 3 | 3 | 1929 | 1950 |
| Saint Louis | 6 | 15 | 7 | 13 | 15 | 1889 | 2017 |
| Saline | 1 | 1 | 1 | 1 | 1 | 2015 | 2015 |
| Scott | 4 | 5 | 5 | 4 | 5 | 1923 | 2015 |
| Shannon | 8 | 9 | 13 | 8 | 8 | 1941 | 2008 |
| Shelby | 3 | 3 | 2 | 3 | 3 | 1961 | 1961 |
| Stoddard | 10 | 15 | 11 | 10 | 10 | 1937 | 2005 |
| Stone | 5 | 6 | 9 | 6 | 6 | 1906 | 2012 |
| Sullivan | 3 | 3 | 2 | 3 | 3 | 1961 | 2012 |
| Taney | 5 | 5 | 7 | 4 | 5 | 1933 | 2012 |
| Texas | 2 | 2 | 2 | 2 | 2 | 1989 | 2002 |
| Vernon | 5 | 5 | 4 | 5 | 5 | 1937 | 2018 |
| Warren | 1 | 1 | 1 | 1 | 1 | 2009 | 2009 |
| Washington | 1 | 4 | 1 | 2 | 2 | 1909 | 1909 |
| Wayne | 10 | 10 | 11 | 10 | 10 | 1935 | 2022 |
| Webster | 5 | 9 | 5 | 5 | 5 | 1959 | 2019 |
| Worth | 2 | 2 | 3 | 2 | 2 | 1982 | 2001 |
| Wright | 3 | 3 | 2 | 2 | 2 | 2003 | 2003 |