Mima Mounds Natural Area Preserve

Mima Mounds Natural Area Preserve is a state-protected Natural Area in southwest Washington state, United States. The preserve includes some of the Washington mima mounds, the origin of which still is not fully understood. The site comprises 637 acre of Garry oak woodland, oak savanna, and prairie grasslands. Several state and federal endangered species of butterfly depending on the unique prairie conditions can be found in the preserve, including Mardon skipper, zerene fritillary, Puget blue and Taylor's checkerspot.

In 1966, the mima mounds were designated a National Natural Landmark.