Sarah Kleinman’s first thought when she came across the large reptile in the woods was that maybe it had gone missing from the Franklin Park Zoo.
“It was definitely the biggest snake I have ever seen,” the Dorchester resident said. “It just looked like it was in the wrong place.”
But wildlife experts said the scaly creature, while very rare in Massachusetts, was exactly where it should be.
While hiking her usual route through the Blue Hills Reservation recently, Kleinman came dangerously close to stepping on a roughly 5-foot rattlesnake slithering slowly across the path.
Kleinman, 45, said she was on a flat trail that was familiar to her, walking with her head down, when she suddenly noticed something about a foot in front of her.
A stick it was not.
“I see this huge snake,” she said. “I almost walked on top of it. My foot might have even been in the air ready to take my next step.”
The sight stopped her “dead in her tracks.” She quickly backed up a few steps to give the snake some space, and once she was at a safe distance took out her phone to record the snake as it passed in slow motion from one grassy side of the trail to the other.
“It wasn’t moving initially,” she said. “Then slowly it started continuing to slither, and it just went on, and on, and on, and on.”
A video shared with the Globe shows the snake’s head near the middle of a dirt portion of the path before it slinks into the grass and disappears.
Kleinman, who encountered the snake roughly a half-mile from the reservation’s Chickatawbut Hill, said she immediately noticed that the snake’s tail had a “rattler,” though it never made a noise.
On the advice of a friend to whom she had shown pictures of the snake, Kleinman reached out to the Department of Conservation and Recreation, the state agency that manages the 7,000-acre park, to make sure the snake was native to the area.
Her suspicion that she had crossed paths with a rattlesnake was confirmed after she spoke to Lieutenant Tom Bender, the department’s South Coast district ranger.
“I texted him the images,” she said. “He said, ‘This is actually really great. I know it was scary, but it looks like it’s a well-grown snake, and definitely a rattlesnake.’ ”
In an interview Wednesday, Bender identified the reptile as a timber rattlesnake, one of two types of venomous snakes in Massachusetts. They are endangered and considered “extremely rare,” according to the state Division of Marine Fisheries and Wildlife.
“It was difficult to see the size from the video, but it looked like a good-sized one,” Bender said. “I explained to her that it’s a very rare sighting, and that she should feel lucky and special that she saw it.”
Bender said he also felt lucky that he picked up the phone that day, and got to see the images firsthand.
“It’s a very unique species that we are striving very hard to protect,” he said.
Mike Jones, herpetologist for MassWildlife, agreed the reptile “looks like a timber rattlesnake.”
Blue Hills Reservation, which spans five communities including Milton, Boston, and Quincy, is among a few locations statewide that timber rattlesnakes call home. They’re known as pit vipers and are usually between 3 and 5 feet long, according to MassWildlife.
“Timber rattlesnakes are native to Massachusetts. Historically they lived in several towns around Boston, including rocky areas of Essex and Middlesex Counties,” Jones said. “The imperiled population in the Blue Hills is small, and it is the only one remaining in Eastern Massachusetts.”
They tend to avoid people and “although venomous, they pose no serious threat when left alone,” according to MassWildlife, which urges hikers “lucky enough” to come across one to report the sighting.
For Kleinman, finding out that the snake wasn’t an escaped attraction from the zoo and was in fact native to the area helped put her at ease.
But she’s not sure she’s quite ready to take that same route through the Blue Hills.
“The day of, I thought, ‘I can’t possibly go on a hike here again.’ But just like anything else, two days later I felt like knowing that the snake was supposed to be there, and it likely wasn’t threatened by me at all, I’ll probably go back,” Kleinman said. “The Blue Hills is just too great not to take advantage of it.”