Mysterious Mima Mounds
Littlerock, Washington
A lumpy landscape stretching into the surrounding forest, hundreds of little knoll-like Mima Mounds pimple an otherwise flat Thurston County prairie. There's an observation deck, a trail that loops around the 445-acre preserve, and an outdoor display that essentially admits that scientists don't know why the mounds exist.
Where they made by wind? Glaciers? Earthquakes? Gophers? Vikings? Each of these explanations has its champions (Well, we're the ones pushing the wayward Vikings theory), but apparently no one has come forward with what would seem to be a definitive cause. In late 2013 a California geologist announced that his computer model favored gophers -- but what made them so hyperactive? Aliens? Vikings???