As far as Harold McAleer is concerned, it started some years ago with a lemonade stand, two kids looking to make a quick buck in the summer, and a pair of the antiquated children’s toys.
“The lemonade stand failed, and the kids went away. But the horsies stayed,” says McAleer, who has lived in Lincoln for 30 years. “Gradually over the years, it has grown and grown.”
Megan Kate Nelson, a Lincoln resident who has documented the growth of the hobby horses in videos and pictures, has a different recollection.
It began with a single horse in 2010, she says. Then, a second one arrived. Soon, the trusty steeds proliferated more quickly than the overgrown weeds and wildflowers that surround them.
Staff in the town clerk’s office? They have no idea.
James Pingeon, whose house adjoins the parcel where the plastic horses roam, says the first one was placed there as part of a holiday display.
“It started out where we had a little Halloween show, and they had a headless horseman in the field, and we didn’t know what to do with the horse afterward,” he said in a message to the Globe. “So we thought, ‘Oh, let’s just leave it in the field.’ ”
Then other horses kept arriving, flying in from everywhere, he said, and gradually the herd expanded.
“It’s a spontaneous art production,” Pingeon said of the dreamlike scene.
Pingeon and his wife, Elizabeth Graver, who own the small parcel, have taken a hands-off approach since the first one showed up. Like many in town, they don’t want to know where the others came from. That’s part of the charm of the display.
“Other people started leaving them, and we just didn’t want to know. There was something lovely about it being anonymous, and now every time we go away, another one appears,” Graver said.
McAleer said he’s added a few of his own.
“It’s whimsical. I think that’s the thing — it’s unusual,” he said. “And people don’t steal them. People contribute to them.”
The rocking horses have a presence that falls somewhere between antique yard sale and spooky prank. Some are made of wood. Others are made of plastic and have rusted springs and broken legs, weather-battered from years of harsh winters and scorching summers.
They appear out of nowhere as you drive through town on Old Sudbury Road. When you round the bend on the two-lane road toward Wayland, you come upon a stretch of sprawling farmland. Real cows and sheep graze in the open fields across from the plastic horses.
In the past year alone, the horse population has nearly doubled, fascinating locals and becoming a recognizable landmark in the bucolic town.
“It has certainly evolved,” said Ray Tomlinson, a sheep breeder who for five years has watched the congregation of rocking horses grow. “We look every day, and sometimes it’s hard to see what’s happened and changed. But a whole lot of new horses have been appearing lately.”
With more than 30 there now, he joked that it might be time to cull the herd.
“They are doubling,” he said.
On Thursday, the horses stood quietly facing each other in a circular pattern. Remnants of one wooden rocking horse lay in the center of the formation, while another charged toward it. The meaning wasn’t clear.
Graver said the horses’ positions change frequently and unexpectedly, as if the plastic horses have moved or migrated of their own free will. But who moves them is a mystery.
During the Kentucky Derby, someone placed the horses in rows as if they were racing. A poster of Triple Crown winner American Pharoah was placed on a stick at the head of the group.
At Christmas time, they are wrapped in holiday lights. Once, they were even arranged as if they were a ghostly carousel, waiting for people to mount them.
Some people — mostly cyclists riding through — call it “PonyHenge” for the way the horses are sometimes arranged. As many as sixty photos of people posing with the horses have been posted on Instagram with the hashtag #PonyHenge.
Everyone is intrigued. Drivers pull over to take pictures. Runners crane their necks and stare with bewilderment.
“There is something about the quietness and mysteriousness of it that I just love,” Graver said.
Steve Annear can be reached at email@example.com. Follow him on Twitter @steveannear.