ARVADA — Scott Snyder balances a wireless speaker on his backyard fence, and with his tablet plays the soundtrack of a rushing highway he plucked off the internet.

The ruckus emanating from the black box is an unpleasant harbinger of what Snyder fears is coming within 100 feet or so of his house — the long-contentious Jefferson Parkway, set to cut through the middle of his Leyden Rock neighborhood in northwest Arvada.

“It’s Denver’s toll road to nowhere,” Snyder said, as he stared out at a wide trench lined on both sides with new homes where the $250 million highway designed to help bring the metro area’s beltway full circle will sit.

Snyder’s neighbor, Michael Raabe, is more blunt about the proposed roadway, which could break ground next year and open for business in 2022.

“This is really going to destroy this community,” he said.

The Jefferson Parkway, four lanes wide and 10 miles long, will run between Rocky Mountain Metropolitan Airport in Broomfield and State Highway 93 north of Golden, skirting the eastern edge of Rocky Flats National Wildlife Refuge. Along the way, it barrels through the middle of Leyden Rock, a community that started rising from the outlying windswept heights of Arvada not more than five years ago.

The prospect of a 65 mph highway bisecting their community has many residents of Leyden Rock jumping mad, and recently they began organizing to oppose it by forming neighborhood groups and crowding city council meetings in Broomfield and Arvada.

Their complaints are familiar ones when it comes to road-building in populated areas: noise impacts, light impacts, poor air quality and the danger of high-speed vehicle debris flung from the tollway into people’s yards. But one worry is specific to the corridor itself: the fear that excavation for the Jefferson Parkway could unearth and disperse deadly, decades-old plutonium from the nearby former Rocky Flats nuclear weapons plant.

Residents worry, too, about grass fires along the road, a situation that becomes all the more alarming given the frequent high winds in the neighborhood.

“It’s not a matter of if a fire happens, but when,” Raabe said.

Residents also criticize the parkway — often touted as the final link in Denver’s yet-to-be finished beltway — for not actually completing the highway ringing the city, instead coming up short at both ends. As currently aligned, the Jefferson Parkway will have no direct connection to either the Northwest Parkway or C-470.

“This was designed to complete the metro beltway, but it doesn’t,” said Snyder, who worries that his house and those of his neighbors will plummet in value once the road is in place. “We’re all going to suffer — we’re not going to benefit at all.”

Those behind the Jefferson Parkway are accustomed to resistance from residents and local governments in the metro area’s northwest quadrant, with battles over the road’s future stretching back decades.

The parkway has caught the wrath of both Superior and Golden, which fear increased traffic on their road systems from the parkway. The project went through a protracted battle in federal court several years ago, as Superior and an environmental group unsuccessfully sued to stop a land swap that was critical to establishing the parkway’s right of way along Indiana Street.

Bill Ray, who heads the Jefferson Parkway Public Highway Authority (JPPHA), said Leyden Rock residents were given fair warning that the highway was coming when they decided to move there. Homebuilders were required to provide disclosures about the parkway to potential homebuyers, and signs were posted along the road’s right of way announcing the Jefferson Parkway’s eventual arrival, he said.

Ray said the JPPHA is open to coming up with ways to lessen the impacts of the highway, whether that’s lowering the elevation of the roadbed or building sound walls to block noise and lights.

“The parkway continues to work with the Leyden Rock neighborhood to make sure noise mitigation and protection of viewsheds are addressed in a way that will accommodate both purposes,” he said. “What can the neighborhood live with and what can the parkway offer?”

The authority’s board is made up of elected leaders from Arvada, Broomfield and Jefferson County, and together the three entities have contributed nearly $20 million to the parkway’s planning process over the last 10 years — money that will be reimbursed once toll revenues start coming in.

The authority is getting ready to put out a request for proposals to three design-build firms that were identified in December. The winning firm, likely to be chosen by the end of the year, will issue bonds to finance the project and use toll revenues collected from motorists to pay back those bonds.

Arvada Mayor Marc Williams, who sits on the JPPHA board, said the project won’t simply go to the lowest bidder but to one that can also address neighbor concerns.

“We’re not just going to slap down some concrete and ignore public safety,” he said.

He said the Jefferson Parkway is an instrumental segment of the last missing piece of beltway and that it will “take patience to get the whole thing done.” He pointed to E-470 on the other side of town, a 47-mile section of the beltway that was built in four phases over more than a decade.

The Jefferson Parkway is needed, Williams said, because growth continues not only in Arvada — with the buildout of thousands of homes in Leyden Rock, Candelas and Whisper Creek neighborhoods over the last few years — but throughout the northwest corner of the metro area as a whole.

The parkway itself will be an economic benefit to the region, according to a 2017 study. The study projected that the parkway would give a $1.2 billion jolt to Jefferson County over a 20-year period.

“I think this has enough momentum to see it through,” the mayor said.

But Leyden Rock residents aren’t ready to lie down. They contend that the disclosures they signed at move-in time were vague as to how big the Jefferson Parkway would be. And they point to toppled over signs announcing the coming of the road that should be posted every 500 feet and remain visible to the public.

“We weren’t ignorant of the parkway, but there was a lot of misinformation,” Snyder said.

Two opposition groups have formed — Movement to Stop Jefferson Parkway and Neighbors of the Parkway — with the former looking to stop the highway altogether and the latter devoted to negotiating with the authority and Arvada to “protect the character, continuity, and tranquility of the Leyden Rock Neighborhood while embracing the need for regional transportation solutions.”

Laura Norman, who aligns herself with Movement to Stop Jefferson Parkway and has lived in Leyden Rock for less than a year, said it won’t be easy to stop a project that has moved ahead this far. But she said it’s worth the fight.

“We’re not just sitting back whining here,” she said. “We have some real concerns.”

An earlier version of this story misidentified the municipality that sued the U.S. Fish and Wildlife Service over the alignment of the Jefferson Parkway. It was Superior.