In archaeological terms, the past is measured in layers.

The older a community is, the more layers can be peeled back to reveal history.

Every so often, that past is unearthed in an unlikely way.

Such was the case recently in the eastern Hancock County town of Sullivan, where it wasn’t archaeologists but a road construction crew who uncovered a bit of history.

“We took a few large pieces of granite out of the road. We’re not quite sure what it is, but it looks like history,” said Dale Mayo, state Department of Transportation engineer for the U.S. Route 1 project.

Townspeople believe the granite artifacts are the remains of an old watering trough that was built in the early 1900s.

According to the Sullivan bicentennial information at the town office, the granite basin was known as the “Band of Mercy” watering trough. Town Clerk Lynn Dunbar explained that it was built in 1910 by children, then donated to Helen Smith, former editor of the Bar Harbor Times newspaper, who owned a pony.

“There used to be a plaque with it, but it was stolen,” she added.

The Sullivan find isn’t a big deal in itself – road crews find things all the time, according to DOT spokesman Herb Thomson. Most of the time, the items are junk and are discarded with the rest of the trash.

But sometimes, artifacts are discovered that have historic value, and the Maine Historic Preservation Commission is always on standby if that happens.

“We’re required by federal law to review most of the DOT’s projects, and sometimes we’ll go out to the scene and dig a little,” said Leon Kranmer, historic archaeologist with the commission. “More and more, people are finding things in unlikely places.”

Unfortunately it’s not often that road crews find anything of value, he said.

Recently the commission was called to check on an old-fashioned cistern in Damariscotta, a granite structure similar to the catch basin found in Sullivan. Kranmer, however, said it wasn’t considered an archaeological find.

The commission also looked into two large stone discs that were found at a site near Fort Knox. They were determined to be old well covers.

Even when the uncovered items aren’t valuable, their findings often spark historical conversations, particularly in Sullivan.

“Things have changed a lot here. The road here used to be in a different area,” said Phil Dunbar, who for 19 years has owned Dunbar’s Store on Route 1 in Sullivan, not far from where the DOT crews found the watering trough. “There was a motel across the street, but they tore it down.”

“The town has really fallen apart,” he said.

Road crews will continue work on Route 1 in Sullivan through the summer, tying up traffic in eastern Hancock County.

Mayo, the project engineer, said if anything else turns up, he won’t hesitate to make a call, but Kranmer at the historic preservation commission said he won’t hold his breath.

“More often than not, if someone is finding something of value, I assume they are keeping it,” he said. “Unless it’s too big to hide.”