Mima mounds are mysterious formations found in fields in various parts of the world, including China, Alaska, and in this part of southwestern Washington. This cluster has been designated a registered natural landmark to preserve and offer interpretations of the formations. The clearing is full of hundreds of closely spaced mounds, six to eight feet high, with a diameter around thirty feet. Various theories exist to explain the mounds, e.g. glacial deposition, erosion, seismic activity, and the burial rituals of Native Americans. In 2013, researchers using both computer modeling and behavioral observation, concluded that it was theoretically possible for pocket gophers to have constructed the mounds over the course of 500 to 700 years worth of burrowing. In 2014, a different team of scientists argued that vegetation spatial patterning (in which single or groups of plants grow in such a way as to cause mound formation due to their effect on soil deposition and erosion), was a more likely cause.