A display directly overhead at Ft. Yukon would appear to be 20 degrees above the northern horizon to someone watching in Fairbanks. If the aurora seems to meet the eastern horizon at Fairbanks, it is nearly overhead in Whitehorse. The apparent convergence of the rays as they extend upward is only a trick of perspective. The rays are actually parallel.
Commercial planes can offer terrific views to passengers on late-night flights.
Thanks to the earth's curvature, auroras over 1000 miles away are visible from a plane flying at 30,000 feet. According to Neil Davis, who is presently writing the Aurora Watcher's Handbook, at times of good visibility and auroral activity, it's possible to see almost one-quarter of all aurora occurring in the Northern Hemisphere from a flight between Seattle and Alaska.