It is the primary airport serving the Inland Northwest, which consists of 30 counties and includes areas such as Spokane, the Tri-Cities, both in Eastern Washington, and Coeur d'Alene in North Idaho.

It is included in the Federal Aviation Administration (FAA) National Plan of Integrated Airport Systems for 2017–2021, in which it is categorized as a small-hub primary commercial service facility.

It was also used by Air Technical Service Command as an aircraft maintenance and supply depot; Deer Park Airport and Felts Field were auxiliaries.

[5] Geiger was closed in late 1945 and turned over to War Assets Administration (WAA), then transferred to Spokane County and developed into a commercial airport.

[12] The project, which concluded in November 2006, added retail space and expanded security checkpoints in the airport's three concourses, and gave the Rotunda an aesthetic renovation.

By 2023, the airport plans to add new gates, centralized security and expanded baggage claim space as it looks to add more direct flights, including to the east coast, to capitalize on and accommodate growing passenger and cargo traffic; the Spokane market has been hosting big events and attracting business to the area.

[13][14] On October 20, 2022, the airport broke ground on the first phase of the project which includes expansion of Concourse C. The $150 million addition will add 144,000 square feet, 6 new gates and modernization of the existing terminal.

[16][17] The second phase of the TREX program is focused on creating a centralized TSA screening checkpoint and baggage claim, as well as an improved operations center.

[23] The new terminal cost a reported US$4,600,000 (equivalent to $44,470,000 in 2023) and was dedicated on May 8, 1965,[24] in a ceremony attended by Senator Warren Magnuson and Civil Aeronautics Board chair Alan Boyd.

The new floors, while sharing some material commonality with the original Heylman and Trogdon concourse, lacked the same curvy and sculpted neo-expressionistic forms.

[26] The project, which broke ground in 1998 added 80,000 square feet (7,400 m2) to the concourse including a new baggage claim and two-story passenger facility.

However, it draws inspiration from its neo-expressionist neighbor by architecturally expressing a modular, repetitive, and exposed structural grid through its façade and interior lobby areas.

The airport is also served by the WSDOT's Travel Washington Gold Line, Northwestern Trailways, Wheatland Express, Queen City Shuttle, and Special Mobility Service.

A consolidated rental car facility is located adjacent to the Ground Transportation Center on the north end of the main terminal.