The Missoula County Airport Authority on Tuesday agreed to the city's request to annex a swath of land east and south of the airfield, setting the stage for guided growth in the years ahead.

The board also approved its first major contract for the initial phase of the new passenger terminal, a project that's slated to begin in January with demolition and be open to the public by the end of 2020.

As the airport and the city eye their convergent futures, both are planning for growth and taking steps to accommodate it. The city acknowledged in May that it was preparing plans to annex areas west of the current city limits, including land surrounding Missoula International Airport.

“The airport did consent back in 1985 or so to annex the land that's already connected to the sewer, and I think that's about 240 acres,” said Lynn Fagan, the airport's administrative manager and legal adviser. “The rest of the airport land, the Deschamps and Pruyn properties that don’t have any development on it, the board needs to consent to annex.”

The board offered that consent Tuesday after city officials answered several questions relating to impact fees, building permits and the design review surrounding the new passenger terminal and other future projects.

Dale Bickell, the city's chief administrative officer, and Mike Haynes, director of Development Services, said the city is currently updating its impact fees, which will likely result in a change to the city's ordinance.

That change, they told the airport authority, would include an exemption for the airport itself, which would likely be zoned as an aviation district under the city's proposed plan.

“State law says that for us to annex, we have to have more than 50 percent of properties sign a petition to annex, and we have about 80 percent,” said Haynes. “We're not relying on the airport and the few parcels that we don't have petitions for at this time. We're just trying to get our ducks in a row and have things wrapped up as we get into the process with the planning board and City Council.”

Haynes said final annexation would likely take place in December, though the city will work with the airport as it transitions from county to city oversight. Changes to the airport itself would be minimal, they said.

Annexation has the support of airport staff, which doesn't believe the changes will impact the terminal project or airport operations.

“At the moment, we still reside in the county, and we've started the review process with the county,” said Cris Jensen, airport director. “Obviously, it looks like annexation is imminent. We'll take our engineers and contractors and go sit down with the city to get them up to speed ahead of time so we can expedite that process.”

That process is set to begin in December as the TSA checkpoint is moved from its current location to the main lobby. The old security wing will be closed from the airport and demolished, starting in January. That will make way for construction to begin on the new concourse next June.

The concourse will include roughly five airline gates and better passenger amenities, such as expanded food and drink options, views of the airfield, and more room to move. The airport has seen rapid passenger growth over the past two years and has grown crowded and obsolete.

Because of that, members of the airport authority said the project can't happen soon enough. They approved a guaranteed maximum price of $10 million for the first phase of work during Tuesday's meeting.

The entire project, funded by grants and airport revenues, is expected to cost around $67 million.

“This package is the demolition of the existing checkpoint building, and then excavation for the new foundation, the concrete for the new foundation and the loading ramp,” said Steve Conway of Martel Construction.

“We also have in here one jet bridge refurbication, three new ramps, design for the other four jet bridges that will happen, and a temporary airline office. We're below our original budget. We feel really good about where we are right now.”