This timelaspe video shows a fireball striking over the Yellowstone National Park on February 29, 2016. But at the end of the footage, 25 seconds after the beginning, a bright flash of light cuts off the silent darkness.
Probably not from the fireball as it disappears already in the first seconds of the video.
Is it a camera flash from tourists visiting the spot at night? This light is not a person on the mound with a flashlight, nor is it a car light, nor are there any street lights, walkway lights, or helicopters flying over. They are not allowed to walk there.
This whole mound is lit up for several seconds, then goes dark. Could it be a rare earthquake light, which releases a form of plasma light energy due to geologic stresses.