Mima Mounds Natural Area Preserve is a state-protected
Natural Area
A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geologic ...
in the southwest corner of
Thurston County, on the
outwash plain
An outwash plain, also called a sandur (plural: ''sandurs''), sandr or sandar, is a plain formed of glaciofluvial deposits due to meltwater outwash at the glacier terminus, terminus of a glacier. As it flows, the glacier grinds the underlying r ...
of the
Vashon Glacier.
It was established in 1976 to protect examples of
mima mounds
Mima mounds are low, flattened, circular to oval, domelike, natural mounds that are composed of loose, unstratified, often gravelly sediment that is an overthickened A horizon. These mounds range in diameter from to more than ; in height to ...
.
The site comprises of
Garry oak woodland,
oak savanna
An oak savanna is a type of savanna (or lightly forested grassland), where oaks (''Quercus ''spp.) are the dominant trees. It is also generally characterized by an understory that is lush with grass and herb-related plants. The terms "oakery" or ...
, and
prairie grasslands.
There are approximately 8-10 mounds per acre, measuring 1-7 feet in height and having a diameter of 8-40 feet.
History
The mounds were documented by
Charles Wilkes
Charles Wilkes (April 3, 1798 – February 8, 1877) was an American naval officer, ship's captain, and List of explorers, explorer. He led the United States Exploring Expedition (1838–1842).
During the American Civil War between 1861 and 1865 ...
on May 20, 1841, who speculated they were burial sites.
In 1966, the mounds were designated a
National Natural Landmark
The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best e ...
.
Recreation
A short, ADA-accessible 0.5 mile paved trail leads to a small interpretive shelter and observation deck with view of the prairie.
A longer, unpaved gravel 1.5 mile loop trail to the south explores the mounds with possible views of
Mount Rainier
Mount Rainier ( ), also known as Tahoma, is a large active stratovolcano in the Cascade Range of the Pacific Northwest in the United States. The mountain is located in Mount Rainier National Park about south-southeast of Seattle. With an off ...
and
Mount St. Helens.
Butterflies
The preserve is host to wildflowers and many species of
butterfly
Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...
(some
endangered
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...
), with activity between spring and early fall, mid-morning and mid-afternoon.
*
Common wood-nymph
*
Coenonympha tullia
*
Vanessa cardui
''Vanessa cardui'' is the most widespread of all butterfly species. It is commonly called the painted lady, or formerly in North America the cosmopolitan.
Description
File:Vanessa cardui MHNT CUT 2013 3 14 Pontfaverger-Moronvilliers Dos. ...
(rare; migratory)
*
Vanessa atalanta
''Vanessa atalanta'', the red admiral or, previously, the red admirable, is a well-characterized, medium-sized butterfly with black wings, red bands, and white spots. It has a wingspan of about . It was species description, first described by C ...
*
Lorquin's admiral
*
Boloria epithore (late April-May)
*
Speyeria zerene
*
Euphydryas editha taylori (endangered)
*
Polites mardon (endangered
)
*
Polites sonora
''Polites sonora'', the Sonoran skipper or western long dash, (late May-August)
*
Ochlodes sylvanoides
*
Papilio zelicaon (May, July-August)
*
Papilio eurymedon (April-October)
*
Papilio rutulus
''Papilio rutulus'', the western tiger swallowtail, is a swallowtail butterfly belonging to the ''Papilionidae'' family. The species was first described by Hippolyte Lucas in 1852.
Like the other tiger swallowtails, the western tiger swallow ...
*
Anthocharis sara
*
Callophrys augustinus
*
Callophrys polios
*
Icaricia icarioides blackmorei
*
Glaucopsyche lygdamus (March-June)
*
Great spangled fritillary (early June-August)
*
Holly blue
The holly blue (''Celastrina argiolus'') Retrieved April 20, 2018. is a butterfly that belongs to the lycaenids or blues family and is native to the Palearctic.
Description
The holly blue has pale silver-blue wings spotted with pale ivory dots ...
*
Parnassius clodius
*
Monarch butterfly
The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. I ...
(rare; not native to region)
Gallery
File:Mima Mounds landmark plaque.jpg, NPS plaque designating the landmark.
File:Tree in Mima Mounds Natural Area Preserve.jpg, Trees and mounds in May 2023.
File:Mima Mounds 04.jpg, Picnic area with view of mounds in March 2021.
File:Mima Mounds observation structure 02.jpg, Observation structure with information graphics.
See also
*
Rocky Prairie
*
Capitol State Forest
References
External links
*
{{authority control
Protected areas of Thurston County, Washington
Washington Natural Areas Program
National Natural Landmarks in Washington (state)
Landforms of Thurston County, Washington
Protected areas established in 1976
1976 establishments in Washington (state)