The Mysterious Mima Mounds National Natural Landmark

Many Theories, But No Definitive Answers


Mima Mounds Trail


There are 599 designated National Natural Landmarks (NNL) in the U.S. and its territories, which are administered by the National Park Service. Washington state is home to 18 of these wonders, and Mima Mounds NNL is one of them. The area provides short, level, unshaded hiking trails which run through this field of small, rounded hills, giving visitors a close-up look and opportunity to imagine how they were formed. Similar mima mounds can be found in other parts of the U.S.; however, they are all named after the Mima Prairie in Washington, which is located southeast of the Capital State Forest.

The more things remain obscure and mysterious, the more they interest me. I even try to find mystery in things that have none.
— Patrick Modiano


Mima Mounds Natural Area Preserve


Mima Mounds Natural Area Preserve


Managed by the Washington State Department of Natural Resources (NAP), the Mima Mounds Natural Area Preserve is a mysterious 637 acres of grassland, forest and oak woodland dotted by unusual domelike mounds of black silt-gravel. Each pile varies in size from 1 to 7 feet tall by 8 to 40-feet in diameter. The hills provide just enough spacing between one another so one can walk around them without having to step over them.

What is intriguing about these mounds is the mystery of their origin. Over 30 explanations have been proposed, some including erosion, earthquakes, and glacial ice, but none have been proven. Similar mounded areas can also be found throughout North America.



Our Visit


Spring flowers at Mima Mounds


We arrived at the mounds around 11:00 AM and began our walk. Informational signs were the first thing we saw as we started down the paved trail followed by a healthy number of spring flowers blooming everywhere. The flowers caught our attention more than the mounds, at first. We stopped and kneeled to capture many photos of flower Camas Lily, Western buttercup, Early Blue Violets, and many more.


Next, we headed to a nearby concrete dome-shaped structure with more signage, including information about prairies, early hypotheses of the mound’s creations, and the various flowers and plants in the area. A quarter of this dome’s roof was cut out with stairs leading up to it. This was a viewing platform which provided just enough of a height advantage over the mounds to see the entire area.


Three main trails lead through the mounds. A half-mile north loop trail, a half-mile ADA loop trail, and a 1.9-mile south loop trail. We started on the ADA loop and headed south. This is a beautiful paved trail that gets you close to the mounds and the many flowers. At the south end of the trail is a second viewing structure, this one made of wood with an ADA ramp to reach the top of it. Here, we looked out again at the beautiful landscape before making our way onto the south loop trail.


The south loop is a gravel trail free of obstacles and relatively flat. This path covers a good portion of the preserve leading around more and more mounds. If you're not up to making the full 1.9-mile loop, there is also a cutoff point which provides a shorter route.

No matter what trail you take, be sure to have sunscreen, sunglasses, and a bottle of water. The entire loop provides no shade and only a couple of benches to take a break on. 


Spring is a fantastic time to visit Mima Mounds. A surprising variety of wildflowers cover this hilly prairie-scape, and spring is the time to see them. Since flowers are in bloom, you will have the added joy of watching butterflies flit from one blossom to another. The usual amber and green tones of the prairie are interspersed with colorful swatches of flower petals, creating a multi-hued quilt of vegetation. If you cannot make a visit during spring, you will still find blossoms and berries through the fall season. 


After we finished the south loop, we were brought back to the ADA loop and finished the west portion of that, which leads through the forested area and back to the parking lot.



Our Thoughts On Mima Mounds


Pacific North Wanderers at Mima Mounds


Mima Mounds is a unique and mysterious place to visit. Whether these mounds were created by natural powers or constructed by natives, we may never know. But it is undoubtedly a worthy spot to wander while you wonder about its origins. If you are interested in doing more hiking, Mima Falls Trail is just a short drive from the mounds.

Are you interested in going to the mounds, or have you already been? Let us know in the comments below!


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Helpful Information for Visiting Mima Mounds

Coordinates: 46.905280, -123.047510
Trail Length: ~3 miles
Difficulty: Easy
Pass Required: Discover Pass


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