Switch frog in industrial trackage next to the San Bruno, California Granite Rock plant. But it sure looks like the Burning Man logo to me…

Shot with the Nikon D70s and the 18-70mm f/3.5-4.5 zoom at 70mm, ISO 400, f/10, shutter 1/320 sec. Cropping, white balance, contrast and levels adjustments in Aperture.