NH's only venomous snake is the most endangered animal in the state. What to know about them

Most snakes in New Hampshire are relatively harmless.

You leave them alone, and they'll leave you alone while keeping your yard's ecosystem in balance (think fewer rodents).

But, there are one species – just one, this isn't the Southwest – that is venomous and whose bite packs a punch: the timber rattlesnake.

The timber rattlesnake is critically endangered, both regionally and nationally, after humans hunted them for decades and due to habitat loss. The snakes are incredibly rare in New Hampshire, likely the most endangered species within the state.

"Since 2007, the population has recovered a bit from a devastating snake fungal disease (SFD) outbreak that was first identified in our population in 2006 that was estimated to kill over half of our remaining population," New Hampshire Fish and Game Department wildlife biologist Melissa Winters said in an email. "New Hampshire’s native timber rattlesnake population is still considered highly endangered and on the brink of extirpation. Up to recent history, timber rattlesnakes were heavily hunted out of fear, which almost resulted in their disappearance from the state."

That population was found by a forester in 1992 after a decade of no one finding a rattlesnake in New Hampshire, which had led to speculation the species had been extirpated, like it is in nearby Maine.

People do occasionally see one, but exactly where they live is a carefully guarded secret to protect that last of these snakes.

But if you do see one of these rare snakes, here's what to know.

Timber Rattlesnake

How to identify: Most timber rattlesnakes have a yellow, brown and black back like the picture seen above. But the New Hampshire timber rattlesnake actually comes in the black morph.

"A large, thick black snake measuring 36-60 inches," the Fish and Game description reads. "Brown cross-bands arranged across the surface may be difficult to see. Has a large triangular head and keeled scales giving them a rough appearance. At the end of the tail there is a large, blunt rattle."

Why New Hampshire only seems to have the black morph isn't known with certainty, "but we speculate that it has been lost due to an overall loss of genetic diversity (a result of their extreme isolation and relatively small population)." Winters said.

The snakes are most commonly confused with the milk snake, northern water snake, black racer snake and garter snake, according to the state, which are all non-venomous species.

The best way to tell the timber rattlesnake apart is the rattle, because while other snakes might try to mimic the rattle, only the rattlesnake actually has one.

Where they are most often found: The location of timber rattlesnakes in New Hampshire is protected information, but scientists believe that historically their range likely included the majority of the state. Some landmarks, such as Rattlesnake Mountain, were likely named for the snakes.

What to do if you get bit: This should go without saying, but try to avoid getting bit in the first place by giving the timber rattlesnake a respectful amount of space. But if the encounter does go awry and you get bit, the good news is that a bite, while painful, is rarely fatal, according to MassWildlife.

Timber rattlesnake bites do have an antivenom. If you are bit, move away from the snake and remove items like rings, bracelets and watches and call for help. Ideally, health experts recommend you get to a hospital with antivenom within one hour of being bit.

What health experts do not recommend is trying to cut out the bite, suck out venom or create a tourniquet.

How to report a sighting: If you see, or even believe you see, a timber rattlesnake in New Hampshire, contact the NHFG Wildlife Division at 603-271-2461 during business hours (Monday through Friday from 8 a.m. to 4 p.m.) or email a report to RAARP@wildlife.nh.gov with rattlesnake observation included in the email subject line. If the sighting is outside of business hours, for an urgent or immediate report people can reach out directly to NHFG wildlife biologists via group text at 603-479-1129 and 603-944-0885 or call. These numbers are only for timber rattlesnakes, all other observations can be sent to RAARP@wildlife.nh.gov.

Photos are appreciated in the report as well as a location and detailed description. However, do not approach a snake to take a photo.

"Under no circumstances should anyone try to capture and get close to the snake as they are protected as a state-endangered species," Winters wrote. "Timber rattlesnakes are not an aggressive and will try to avoid interactions with people. Most of the time they will try to blend into their surroundings and remain still to avoid being seen as a defense strategy. However, if they are surprised or feel threatened they will try to flee, like most wildlife species, or may coil up in a defensive posture (i.e. a strike pose) so if they are attacked, they can defend themselves."