A historic ferry landing ramp in Coupeville was inadvertently reduced to rubble this week during a demolition project designed to remove an aging structure that rested on top of it.

Island County Public Works spent Monday demolishing a small World War II-era rake station once used by the Navy at its county-owned Driftwood Park along the Keystone Spit.

What the county was unaware of was that the structure was constructed atop a concrete ramp believed to be about a century old that once served as the terminus of the Coupeville-Port Townsend ferry route before the present-day Keystone Harbor landing started being used in 1948.

Crews used heavy machinery to dismantle the building, its foundation and the ramp beneath it, loading the rubble on to trucks before filling in the area with rock and dirt.

But when the dust settled, a problem emerged.

“Nobody mentioned this historic ferry landing,” said Bill Oakes, Island County Public Works director.

The project went through the proper county permitting process, Oakes said, and was reviewed by an advisory committee through the Historic Preservation Commission.

None of those channels revealed the existence or significance of the former ferry terminal ramp that was visible above ground in an area frequented by beach walkers and salmon anglers.

Fishers referred to the structure as the “pump house.” More than a half century ago, it was a naval “rake station” where observers would track the accuracy of bomb drops in Greenbank during training exercises.

What it rested on dated back much further.

“When we were approving it we were looking at the building and thinking it was on a heavy foundation,” said Sarah Steen, preservation coordinator with Ebey’s Landing National Historical Reserve who served on the advisory committee. “It just got missed.”

Steen said that neither the military building nor ramp underneath it existed in the reserve’s historic structures inventory, which might’ve otherwise avoided the ramp’s demolition.

The building needed to be removed because it was starting to pose a safety concern, Oakes said.

“I spend a lot of time here,” said Oak Harbor’s Patrick Dyer, who was walking his dog around the site Tuesday morning.

“I’m glad it’s gone. It was kind of an eyesore.”

Steve Kobylk, an Admirals Cove resident and state parks volunteer who is considered a local expert on nearby Fort Casey, had trouble understanding how the mistake could have occurred.

“It sounds like they didn’t know the difference between a rake station and a ferry ramp,” he said.

Kobylk said he had informed the reserve about the historic ferry ramp about 10 years ago and noticed with keen interest when the county posted a notice of application on a fence next to the building a few months ago.

He felt the ferry landing ramp would be safe because the notice called for removal of a “non-contributing structure within Ebey’s Landing National Historical Reserve.”

“When I saw Ebey’s Landing Historical Reserve, I thought, ‘Oh everyone’s seen it. Everything’s fine.’”

He found out otherwise Monday, watching a historic landing crumble away.

The ramp used to serve as a one-lane entry to Coupeville for ferry-goers.

The concrete pilings remain just offshore.

“Any little piece like that might seem insignificant as it stands by itself,” said Rick Castellano, executive director of the Island County Historic Society Museum, “but it’s all part of the historical landscape here. When something like that goes away, it’s gone forever.”