Eight miles south of Tumwater is the Mima Mounds Interpretive Area (Waddell Creek Rd. S.W., 360/753-2449, dawn–dusk daily) a registered national landmark with nature walks, an interpretive center, and picnic area. These grass-covered mounds, ranging in height up to eight feet, are also scattered throughout southern Thurston County, parts of China, and Alaska.
They're often referred to as "mysterious" because no one really knows how they got there; theoretical origins range from glaciers to giant gophers, although the latter theory comes mainly from the same folks who brought you the "jackalope."
Native Americans burned these areas to keep them open and productive, but today Douglas fir trees are gradually spreading across the hilly mounds.
© Ericka Chickowski from Moon Washington, 8th edition