Mima Mounds Natural Area Preserve

People have argued about the Mima Mounds for well over a century, and the theories are wonderfully varied. The one with the most staying power came in 1942, when a University of Washington student and a federal biologist proposed in a geology journal that generations of pocket gophers, pushing soil toward their burrows, slowly built the mounds up over time.

Others have looked to bigger forces. Some geologists argue the mounds were left by a glacial outburst flood in the Puget lowland during the last Ice Age. In 1990 a geologist suggested that the shaking of earthquakes could pile loose soil into regular mounds. Still other ideas involve sediment dropped into melting ice pits, or the way water-soaked ground heaves as it freezes and thaws. As of today, no explanation has won out, and that unresolved argument is much of what makes the place worth seeing.

Long before the mounds were a curiosity, this was prairie, and prairie is now one of the rarest habitats in western Washington. Most of the Puget lowland's open grasslands were plowed, paved, or grown over with forest once the fires that once maintained them stopped. Mima Mounds, protected as a preserve in 1976, is one of the finest surviving remnants.

For thousands of years these prairies were not simply wild. Coast Salish peoples of the south Puget Sound tended them with regular burning that kept the forest back and encouraged camas, the blue-flowered lily whose bulb was a staple food. The open, mound-dotted grassland you walk through is in part a landscape that Native people shaped and kept.

In spring the prairie comes alive. Camas turns whole swaths of the ground blue, and it mixes with buttercup, western blue-eyed grass, shooting star, and later the drifts of native flowers that make an April or May visit unforgettable. This is also prime habitat for rare prairie species, including butterflies and birds that depend on the vanishing grassland.

Look for hawks hunting over the open ground, listen for meadowlarks, and watch for the pocket gophers whose diggings, fittingly, are still part of the story. In summer the prairie dries to gold, and in the quiet months it is a peaceful place to walk and puzzle over the ground beneath your feet.

The closest Boutel™ stays, so you can turn this stop into an overnight. Each is a place we chose through independent editorial review, never a paid placement.

The Mima Mounds Natural Area Preserve, near the town of Littlerock south of Olympia in western Washington, protects a mysterious and fascinating landscape of thousands of low, rounded earthen mounds spread across a prairie. These curious mounds, which can be several feet high and many feet across, have puzzled scientists for generations, with various theories about their origin, from ancient earthquakes to burrowing animals, though no single explanation is universally accepted, adding to their intrigue. Preserved as a rare native prairie with wildflowers and interpretive trails, the Mima Mounds offer a unique and enigmatic natural site. With its mysterious mounds, prairie, and trails, the Mima Mounds Natural Area Preserve is an intriguing destination in western Washington.

The origin of the Mima Mounds remains a genuine scientific mystery, and no single explanation is universally accepted, which is part of what makes them so intriguing. Over the years, scientists have proposed many theories, including the work of burrowing animals like pocket gophers building up soil over long periods, ancient earthquakes shaking loose soil into mounds, glacial or flood processes, and freeze-and-thaw cycles, among others. Each theory has supporters and skeptics, and the debate continues. This enduring uncertainty about how the thousands of mounds formed gives the Mima Mounds their enigmatic appeal, inviting visitors to ponder the puzzle for themselves.

You can walk the interpretive trails, including a paved loop and longer paths, through the field of mysterious mounds, learn about the various theories of their origin at the interpretive kiosk, enjoy the rare native prairie with its wildflowers, especially beautiful in spring bloom, watch for birds and wildlife, and simply ponder the enigma of the mounds. The trails are relatively easy, making it accessible. The prairie is a lovely and unusual landscape. With its mysterious mounds, interpretive trails, and native prairie wildflowers, the Mima Mounds Natural Area Preserve offers an intriguing and pleasant outdoor experience in western Washington.

Spring is especially wonderful, when the native prairie bursts into bloom with wildflowers covering the mounds, creating a beautiful display, typically peaking in late spring, while summer and fall offer pleasant weather for the trails and winter is cooler and quieter. The mounds are intriguing year-round, but the spring wildflowers add special beauty. Mornings are pleasant for the walk. For the most beautiful scenery with the prairie in bloom, aim for spring, while the trails and the mystery of the mounds make the Mima Mounds Natural Area Preserve rewarding in any season.

The Mima Mounds Natural Area Preserve is near Littlerock south of Olympia in western Washington, near the state capital of Olympia, the Capitol State Forest, and within reach of the South Puget Sound area, the town of Tumwater, and Interstate 5. That makes the Mima Mounds Natural Area Preserve an intriguing natural stop to combine with Olympia, the Capitol State Forest, and the other attractions of the South Puget Sound area on a visit to Washington.