Facility upgrades at Spokane International Airport continue this year with multiple developments underway to improve passenger boarding, strengthen infrastructure, and increase office space at the major transportation hub.

Construction is proceeding on the first phase of the Terminal Remodeling & Expansion, or TREX, program, which will significantly expand one of three airport concourses, says Alannah Toft, marketing and communications manager at the airport.

The first phase of the TREX program is the Concourse C expansion project, which has two segments: Concourse C West and Concourse C East. The entire first phase of TREX is valued at $150 million.

Current work is addressing Concourse C East terminal upgrades, including the replacement of existing ground boarding gates with three new passenger boarding bridges and updates to three existing gates in the concourse, Toft says.

Construction of Concourse C East began last spring—following the completion of Concourse C West—and is expected to wrap up in the third quarter of 2026. 

Concourse C West improvements debuted in May 2024 and involved the addition of three new gates and six ticketing counters.

Once all work is completed, 144,000 square feet of space will have been added to Concourse C, she says.

The entire Concourse C expansion is being constructed through a joint venture between Spokane-based general contracting company Garco Construction Inc. and Q&D Construction LLC, a Sparks, Nevada-based airport general contractor.

The Concourse C expansion is one piece of the airport's long-term vision to enhance and expand terminal capacity to accommodate growth in the Inland Northwest region. In the future, Spokane International Airport plans to pursue the second phase of the TREX program, which involves upgrades to the facility's Central Hall to consolidate security screening checkpoints and baggage claim areas, she says.

Separate from TREX, the airport also is working on the rehabilitation of Taxiway Alpha, an 11,000-foot path that commercial and cargo planes use to access the airport's primary runway. 

In September 2024, the airport received $18 million in federal grant funding from the Federal Aviation Administration, as part of the U.S. Department of Transportation's Airport Improvement Program for the taxiway project, Toft says.

The taxiway improvements are planned in two phases that will replace 4,000 lineal feet of asphalt with a more durable concrete surface aimed at strengthening the structural integrity of the pavement for heavy aircraft use, she explains. Taxiway lighting also will be replaced with LED lights and new airfield signage will be installed to help pilots navigate on the ground. 

The first phase of the taxiway project is anticipated to be completed in the second quarter of this year. The second phase currently is out to bid and is expected to be completed in Q2 2026.

Spokane-based Shamrock Paving Inc. is the contractor on the first phase of work on Taxiway Alpha. Contractor bids are out for the second phase of construction, with a selection expected by April.

Jacksonville, Florida-based RS&H Inc. is the project engineer for both phases of the taxiway improvements.

Groundwork is underway for a third airport project that will increase administrative capacity at the property, and is anticipated to be completed in the fourth quarter of 2025, Toft says.

Design plans and a projected cost for a proposed administrative office building are currently under review.

Spokane-based Bouten Construction Co. has been selected as the general contractor for office building project, she says. 

San Francisco-based MWA Architects Inc. is designing the building, according to a pending permit application on file with the city of Spokane, which lists an estimated construction cost of $11.4 million for the interior buildout.