Crotalus horridus: By virtue of their large size, timber rattlers are the most dangerous snakes in northeastern America. Fortunately, when encountered most timber rattlers are mild in disposition unless aroused, and make little attempt to rattle or strike. It is believed to have occured in at least 25 counties prior to 1800. Today, the timber rattlesnake is listed as an endangered species by the Ohio Division of Wildlife and is known from only seven Ohio counties.
In the Field - Gallery - Joel Sartore
A western diamondback rattlesnake (Crotalus atrox) in the foothills of the Wichita Mountains in Oklahoma. Studies are showing that rattlesnakes that have the genetic tendency to migrate are being killed in ever-increasing numbers on our nation's roads, leaving those snakes with non-migrating tendencies behind to breed.
Massasauga (Sistrurus catenatus) - Reptiles of Arizona
Sistrurus catenatus: Eastern massasaugas are becoming increasingly rare in North America and are now endangered throughout much of their range. As with many other species, human disturbance of their habitat, particularly through farming, has led to their reduced numbers in Ohio. They have been recorded in as many as 22 counties; however, they are a rare sight. The Eastern massasauga is one of three venomous snakes in Ohio.