Glacier Park International Airport (GPIA) is preparing for an important runway rehabilitation project to extend the runway’s service life and maintain safe, efficient air travel in the Flathead Valley. Construction will occur in July 2026, with additional nighttime work in September.
July 2026 Closure Schedule
Phased Weekday Closures for Minimal Disruption
GPIA will implement phased weekday closures throughout the month of July.
Runway Closed
Monday at 6:00 p.m. – Friday at 10:00 a.m.
Closure Dates:
- July 6–10
- July 13–17
- July 20–24
- July 27–31
The runway will reopen for flights every weekend (Friday–Monday), to align with peak travel demand and maintain service during construction.
Nighttime Work in September
Approximately 15 nightly closures between 12:30 a.m. and 5:30 a.m. will be required for runway surface grooving. This work will be complete by October 1. This is essential for creating adequate friction for winter flight operations. These short late-night closures are not expected to impact flight schedules.
Why This Project Is Needed
Runway pavement has a defined lifespan, usually 15 to 20 years. GPIA’s main runway was last rehabilitated in 2009, making it 17 years old in 2026. The runway has begun showing signs of surface wear and deterioration. Timely rehabilitation is important to avoid more extensive and costly repairs and maintain eligibility for federal funding.
Thoughtfully Considered and Carefully Planned
Though July is a peak travel season, it’s also the most favorable month for the construction activities. Based on two decades of weather data, July offers the most consistent dry conditions and nighttime temperatures above 50°F, which are required by Federal Aviation Administration specifications. Conducting the rehabilitation activities in July minimizes the risk of weather delays and unplanned extended closures.
Twenty-year weather assessments showed the probability of having the necessary weather conditions from April through September. Each month’s probability of favorable weather conditions are as follows:
April: 1%
May: 10%
June: 33%
July: 81%
A 30-day waiting period is required between paving operations and runway grooving. The probability of consistent favorable weather conditions in August and September was not evaluated since conducting the paving activities in these months does not allow time to complete runway grooving following the waiting period and before winter weather sets in. In the interest of runway safety, delaying grooving operations to the following year is not an option.
Strategic Planning
The rehabilitation strategy was developed in collaboration with experienced airport engineering teams. Multiple alternatives were carefully considered. The selected approach balances safety, quality, cost efficiency, and community impact while allowing for defined, predictable disruptions instead of risking unexpected delays that would disrupt travel for more than 6,000 passengers each day.
Mitigating Impacts
Airline Coordination
GPIA is working closely with the airlines to ensure schedules and flight bookings are adjusted for the closures. Although there will be flight schedule impacts, 60% of all flights will still occur during open hours.
Each airline will determine if additional flights or larger planes are necessary to adapt to increased travel during the airport’s open days. GPIA will work to accommodate additional flights wherever possible.
Continued Access to the Flathead Valley
According to University of Montana Institute for Tourism and Recreation Research data, only 14% of visitors to the Flathead Valley have arrived by air during Quarter 3 between 2019 and 2024. By maintaining 60% of the July flight schedule during construction, Flathead visitation impacts will be minimal.
During construction, visitors will continue arriving by car and through nearby regional airports. With a predictable schedule in place and weekend flights maintained, the Flathead Valley remains open for business and ready to welcome guests.
Stay Informed
GPIA is committed to keeping the community and travelers informed. This page will be updated throughout the process. Please check back often to stay in the know.
Thank you for your patience and support as we complete this important project.