The Bonneville Salt Flats is a densely packed salt pan in Tooele County in Utah. The area is a remnant of the Pleistocene Lake Bonneville and is the largest of many salt flats located west of the Great Salt Lake.
The property is public land managed by the Bureau of Land Management and is known for land speed records at the Bonneville Speedway. Access to the flats is open to the public.
On July 2, a giant alien mothership enters orbit around Earth and deploys several dozen saucer-shaped 'destroyer' spacecraft that quickly lay waste to major cities around the planet. On July 3, the United States conducts a coordinated counterattack that fails. On July 4, a plan is devised to gain access to the interior of the alien mothership in space, in order to plant a nuclear missile.