I've been doing extensive research on finding pictures of the Hanford Nuclear Site located in eastern Washington containing various LPS luminaires installed there. I initially found out about this when I watched a documentary regarding Hanford in class back in seventh grade history class. Now that I've found photos and Street Views, I'd like to show everyone my findings.
My theory as to why they're there is most likely because of LIGO, which stands for "Laser Interferometer Gravitational-wave Observatory." Built in 1992, it was (and still is) used to detect gravitational wave vibrations from outer space. However, the real reason is unknown.
Photos:
Street Views: