Wow! C-17 pass in the famous Mach Loop by the 315th Airlift Wing - a Reserve Wing at Joint Base Charleston. Amazing video by @h18pdwphotography.co.uk
This is the first time the huge Boeing C-17 has made this kind of low level pass in the Mach Loop, it's usually done by smaller jets.
The Mach Loop is a set of valleys, situated between Dolgellau in the north, and Machynlleth in the south (and from which the Mach Loop gets its name), which are regularly used for low level flight training, with flying as low as 250 feet (76 metres) from the nearest terrain. (credit: Machloop.co.uk)