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.

[2] The site comprises 637 acres (258 ha) of Garry oak woodland, oak savanna, and prairie grasslands.

[3][4] 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.

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