An annual snake survey in Ohio revealed an unexpected find – an eastern Massasauga rattlesnake, an "increasingly rare" snake in the state that is considered threatened. 

The Ohio Department of Natural Resources said one of its officers in Huron County found the rattler in May. Officials captured the snake, recorded its measurements, and then released it back into the wild. 

Eastern Massasaugas are "small snakes with thick bodies, heart-shaped heads and vertical pupils," according to the U.S. Fish and Wildlife Service. They only grow to be about 2 feet long and have gray or light brown skin with "chocolate brown blotches on the back." Those considered melanistic appear as all black. They've been found in Illinois, Indiana, Iowa, Michigan, Minnesota, New York, Pennsylvania and Wisconsin.