Tri-State Spook Light aka Hornet Spook Light
Quapaw, Oklahoma
One of the few consistently performing mystery lights in the U.S., glowing since 1881, and named the Hornet Spook Light (after a now defunct town). Investigated without satisfaction by U.S. Army Corps of Engineers in 1946, which declared it a "mysterious light of unknown origin."
The orbs are visible at night (when they choose to appear) along a four mile stretch of the gravel Oklahoma East 50 Road, also called the "The Devil's Promenade" and "Spook Light Road." Current explanations blame it on lights refracted through the woods from nearby highways, or escaping subterranean gas, or piezoelectric energy created by quartz crystals rubbing together underground. Or ghosts.
At one point in its history there was a local general store maintaining a Spook Light Museum, but that has been closed for decades.