A controversial push by federal aviation authorities to shift westbound flights out of Denver International Airport over Gilpin County appears to have come at the suggestion of one person looking to clear the skies above Boulder.

In a recent supplemental report to a final environmental assessment of the Denver Metroplex Project obtained by The Denver Post, the Federal Aviation Administration wrote that during its community engagement process last year “a member of the public proposed the FAA move (a westbound flight path over Boulder) further south.”

The result of that advice from the unnamed person: a planned “lateral shift” of all those planes 2 nautical miles to the south from their existing route “over the south/central City of Boulder,” according to the FAA document.

Gilpin County Commissioner Gail Watson said the change places the flight path — dubbed ZIMMR SID — right over her sparsely populated but historically significant county, which formed 15 years before Colorado became a state.

“They took one person’s recommendation to move the flight path — why didn’t that trigger a conversation with the county that would impact?” Watson said Thursday.

Residents of Gilpin County, she said, never got a meeting with the FAA as it rolled out the latest iteration of its Denver Metroplex Project, an initiative that strives to redesign airspace and address inefficiencies through new navigational technology and realigned flight paths. It has not yet been finalized.

The agency projects that the streamlined flight paths, which promise smoother descents than the traditional stair-step approach pilots take today, will save more than half a million gallons of fuel annually at a cost savings of $1.8 million.

The agency held dozens of public workshops on Metroplex across the metro area last year and before that in 2017, including in Boulder, Littleton, Centennial and Brighton.

But not in Gilpin County.

“We never got a voice in it,” Watson said.

FAA spokesman Allen Kenitzer on Thursday said noise modeling and feedback from elected officials were used to determine the locations for public workshops on Metroplex.

“The public workshop locations, dates and times were posted on the FAA Community Involvement and Denver Metroplex Project websites, in addition to being publicized through social media and press releases,” he said. “Gilpin County has specifically been invited to review and comment. Both the Draft EA and the Final EA were sent electronically to the Gilpin County Public Library upon public release.”

He said there are no plans for FAA officials to meet with Gilpin County residents at this time.

“Air traffic levels are a function of community demand for air service and the industry responds to serve that demand,” Kenitzer said. “The Denver Metroplex procedure is to accommodate demand safely and efficiently.”

Gilpin County has been agitating for months about planned flight paths out of DIA, charging the FAA with not taking adequate measures to gauge how a concentration of new overhead flights will affect the mountainous county.

“They have no idea what the impact is to our cultural and historic resources; they have no idea what the impact is on our wildlife; they have no idea what the impact is on our residents,” Watson said.

The Denver Metroplex Project has been under fire from communities beyond Gilpin County. Boulder County residents registered complaints about flights out of DIA during public workshops last year while Denver’s southern suburbs are worried about the project exacerbating noise impacts from air traffic moving in and out of Centennial Airport.

Watson said she expects Centennial Airport to file a lawsuit against the FAA over Metroplex any day now and Gilpin County, she said, will file an amicus brief in support of the legal challenge.

In the meantime, U.S. Sen. Michael Bennet and Rep. Joe Neguse, who represents both Boulder and Gilpin counties in Congress, have asked the FAA to re-open the public input period on Metroplex’s environmental assessment and grant residents there a formal meeting.

On Thursday, a spokeswoman for Neguse said the congressman has “also advocated for noise sampling to be done to better take into account geographical features in the area.”

“Gilpin County is home to the James Peak Wilderness Area and Golden Gate Canyon State Park — both of which are treasured public lands that would be greatly disturbed by an increase in air traffic overhead,” said Sally Tucker, Neguse’s spokeswoman.

Earlier last week, Colorado House Speaker KC Becker and state Sen. Tammy Story met with dozens of Gilpin County residents to hear complaints about Metroplex.

“It’s critical that the FAA do a better job of communicating with local communities,” Becker said Thursday. “It sounds like they are completely ignoring all the local input.”

The speaker said she plans to reach out to the Colorado attorney general’s office to see if there are grounds to take legal action against the FAA from a state perspective.

Christine Weeber, who moved to Gilpin County in 2005 to escape severe environmental sensitivities to mold and synthetic fragrances, said she and her husband managed to build a “safe, nontoxic home” to live in.

“This is my hospital, my refuge, my second skin, my living space, and my workspace,” she said.

But increased air traffic overhead could degrade her lifestyle, Weeber said, as well as jeopardize birds of prey — northern goshawks in particular — that live in the area.

“I feel there should be an awareness that they need a healthy, quiet forest to live in,” she said. “We don’t want to lose them.”

Watson, the commissioner, said she doesn’t want flight paths moved over someone else in an effort to evade the noise in Gilpin County. She just wants fairness from the FAA.

“Our position isn’t put all the air traffic over Boulder or put all the air traffic over Clear Creek County,” she said. “Our position is — spread the pain.”