Spokane International Airport's Terminal Renovation & Expansion, or TREX, program is on schedule to complete the first phase of construction in the third quarter, says Alannah Toft, marketing and communications manager at the airport.

The first phase of the TREX program, valued at $150 million, involves the Concourse C expansion project, which has two segments: Concourse C West and Concourse C East. Improvements to Concourse C West debuted in May 2024 and included the addition of three new gates and six ticketing counters.

Terminal upgrades at Concourse C East, which began shortly after completion of Concourse C West, include the replacement of existing ground boarding gates with three new passenger boarding bridges and updates to three existing gates, the Journal previously reported.

Those improvements are set to be completed later this year, says Toft.

The Concourse C expansion project is being constructed through a partnership between Spokane-based Garco Construction Inc. and Q&D Construction LLC, a Sparks, Nevada-based airport general contractor. The Alliiance Inc., an architectural design firm based in Minneapolis, designed the Concourse C expansion, Toft says. 

The second phase of the TREX program is currently in the design phase and will upgrade the facility’s Central Hall to consolidate security screening checkpoints for all airlines, with a post-security hallway connecting the A, B, and C Concourses. Improvements also will consolidate the baggage claim area and establish a new operations center, according to the airport’s website. Alliiance is providing design work for the Central Hall project, Toft says.  

According to information from the airport's website by the Associated General Contractors Construction Multiplier, the Concourse C expansion is expected to create nearly 1,200 jobs, bring $87 million of additional household revenue to the Spokane region, and generate $314 million of economic activity in Washington state.

Also underway at the airport is the rehabilitation of Taxiway Alpha, an 11,000-foot path that commercial and cargo planes use to access the primary runway.

As previously reported by the Journal, the two-phase taxiway improvement project 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. 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 Alpha upgrades was completed in 2025, and the second phase is expected to be completed in the second quarter of this year, Toft says.

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

The taxiway improvements are funded by an $18 million federal grant from the Federal Aviation Administration as part of the U.S. Department of Transportation’s Airport Improvement Program.

Construction of a new administrative building is also in progress at the airport. The new $37 million building is expected to open by the end of the year, Toft says.

Bouten Construction Co., of Spokane, is the contractor for the administrative building, and San Francisco-based MWA Architects Inc. designed it.