Select your current world region and subregion.
| Occurrences in | |
|---|---|
| NW | the Northwest |
| N | the North |
| NE | the Northeast |
| W | the West |
| C | central areas |
| E | the East |
| SW | the Southwest |
| S | the South |
| SE | the Southeast |
| X | most areas |
| ? | unclear |
| Micrurus albicinctus | NE+C+SW | |
| Micrurus alleni | X | Oklahoma only |
| Crotalus atrox | X | Oklahoma only |
| Crotalus horridus | E | |
| Crotalus viridis | X |
| Sistrurus catenatus | NE+C+SW | |
| Sistrurus miliarius | X | Oklahoma only |