It was filmed in our neck of the woods. The “old” airport scene set in Colorado was filed at Ephrata, Washington and I’ve just heard one of the old WWII hangars has been sold to a Seattle-area warbird collector. He’ll move it to his location.
The owner of the PBYs used in the film had another unconverted PBY-6A, the last Catalina produced. It’s new owner is restoring it to fly at the Grant County Airport in Moses Lake, Washington.
I met the owner a couple of years back, a nice guy and he’s still working on it. He’s working hard to make it 100% authentic.

Also, the firebase scene was filmed at Libby, Montana which isn’t normally a firebase, the production people did it all from scratch. When the film came out, I wrote Speilberg’s production company and they sent me a nice detailed report of the various film locations.

The wheat filed scene was also filmed just down the road….I’ve always found it ironic that Audrey Hepburn, a huge international star, did her final film in the middle of nowhere…Sprague, Washington.