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Indiana Dunes National Park

Indiana · Established February 15, 2019

Singing sands, quaking bogs, and the birthplace of ecology on Lake Michigan

Area: 15,349 acres
Established: February 15, 2019
Recreation visits: 2,629,497 / yr
State: Indiana
Tallest dune: Mount Baldy, about 123 ft (37 m) above the beach
Lowest point: Lake Michigan shoreline, about 580 ft (177 m) above sea level

Indiana Dunes Weather Forecast

Loading the National Weather Service forecast for Indiana Dunes…

Seven-day outlook at the park's reference point (41.638, -87.097). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of Indiana Dunes National Park

The Park

Along fifteen miles of Lake Michigan's southern shore, between the steel mills of Gary and the harbor at Michigan City, lies one of the most biologically rich landscapes in the Midwest. Wind and waves have heaped sand into dunes more than a hundred feet high, and behind them lie black oak savannas, tallgrass prairie, marshes, swamps, and bogs that hold northern relics like tamarack and pitcher plants.

It was here, at the turn of the 20th century, that University of Chicago botanist Henry Chandler Cowles walked from bare beach to mature forest and recognized a sequence of plant communities replacing one another over time. His work on ecological succession helped found the science of ecology, and it inspired a long campaign to protect the dunes that led to a national lakeshore in 1966 and a national park in 2019.

Geography

Indiana Dunes National Park is a patchwork of protected lands scattered along the northwest Indiana shoreline, interwoven with towns, industry, and Indiana Dunes State Park. It stretches from Miller Woods in Gary eastward past Portage, Dune Acres, and Beverly Shores to Mount Baldy near Michigan City, and inland to Pinhook Bog and the Little Calumet River.

The land rises in parallel belts that record the retreat of ancient lake shorelines. Nearest the water are beaches and active foredunes; behind them lie older, forested dune ridges, interdunal wetlands such as the Great Marsh, and farther inland the arcs of glacial moraines. Relief is modest in feet but dramatic on the ground, as dunes rise abruptly from the beach.

Few national parks are so accessible: Chicago lies less than an hour away by car or commuter train, and more than 50 miles of trails lead through the park's habitats.

Landmarks

Mount BaldyDuneA wandering dune about 123 feet high that has migrated inland several feet a year, burying trees as it goes.
West BeachCoastA broad swimming beach whose trails climb through a textbook sequence of dune succession.
Cowles BogAreaA wetland complex of bog, fen, marsh, and swamp named for pioneering ecologist Henry Chandler Cowles.
Pinhook BogAreaA quaking sphagnum bog in a glacial kettle, with pitcher plants, sundews, and tamaracks.
Miller WoodsAreaBlack oak savanna, ponds, and dunes at the park's western end in Gary.
Bailly HomesteadAreaThe early 19th-century trading post of Joseph Bailly beside the Little Calumet River.
Little Calumet River (East Arm)RiverA slow, meandering river that drains the lowland behind the dunes.
Portage-Burns WaterwayRiverThe Little Calumet's outlet to Lake Michigan beside the park's Portage Lakefront.

Geology

The Indiana Dunes are a gift of the Ice Age. During the last glaciation, a lobe of the continental ice sheet pushed south through the Lake Michigan basin. As it paused and melted back, it left curving ridges of debris, including the Valparaiso Moraine, whose arc still frames the southern end of the lake, and younger moraines closer to the shore.

Meltwater pooled between the moraine and the retreating ice, forming glacial Lake Chicago roughly 14,000 years ago. Its level rose and fell as outlets opened and closed and as the land rebounded from the weight of the ice, passing through later stages known as Lake Algonquin, Lake Chippewa, and the Nipissing Great Lakes. Each stable level built a beach and dune ridge, so the landscape now holds a staircase of ancient shorelines stepping inland from the modern beach.

Today's dunes form where prevailing westerly and northwesterly winds sweep across Lake Michigan and push beach sand inland. Where marram grass and cottonwoods catch the sand, dunes grow; where vegetation is lost, blowouts open and dunes march downwind. Mount Baldy is a classic moving dune, advancing over the forest behind it.

Between the dune ridges, water collects in low swales to form marshes, swamps, and fens. In kettle depressions left by buried ice blocks, such as Pinhook Bog, sphagnum moss built acidic, floating mats where plants of the far north still grow.

Deep time

Paleozoic, hundreds of millions of years agoLimestone and shale bedrock form beneath a shallow sea, now buried deep under glacial deposits.
About 40,000–14,000 years agoIce sheets advance and retreat, building the Valparaiso Moraine and younger moraines.
About 14,000 years agoGlacial Lake Chicago forms at the southern end of the Lake Michigan basin; kettle bogs like Pinhook begin to form.
About 9,000–7,000 years agoLake levels swing through the Algonquin and Chippewa stages as outlets change.
About 4,000 years agoThe Nipissing high stand builds dunes and shorelines inland of today's beach.
1899Henry Chandler Cowles publishes his landmark study of plant succession on the dunes.
PresentWind and waves continue to build, erode, and move dunes along the shore.

The rocks

Valparaiso MoraineLate Pleistocene
A broad arc of glacial till marking a major stand of the ice sheet south of Lake Michigan.
Tinley and Lake Border morainesLate Pleistocene
Younger recessional moraines closer to the lake.
Glenwood, Calumet, and Tolleston shorelinesLate Pleistocene to Holocene
Beach ridges left by successive stages of glacial Lake Chicago and later lakes.
Nipissing dunesMiddle Holocene
High, forested dunes built during the Nipissing high-water stage.
Active foredunes and blowoutsModern
Wind-shaped sand hills, including the moving dune Mount Baldy.
Kettle bog peatHolocene
Sphagnum peat accumulated in ice-block depressions such as Pinhook Bog.

Trees, Plants & Ecosystems

1,430vascular plant species recorded

Beach and foreduneLake level to dune crest
Marram grass, sand reed, and cottonwood capture blowing sand; piping plovers and sanderlings forage on the beach.
Black oak savannaOlder dune ridges
Open groves of black oak with lupine, prickly pear, and prairie grasses, maintained by fire.
Interdunal wetlands and the Great MarshLow swales between ridges
Marshes, fens, and swamps rich in sedges, rushes, frogs, and nesting birds.
Mesic hardwood forestSheltered ravines and back dunes
Beech, sugar maple, basswood, and tulip tree grow on moist north-facing slopes with spring wildflowers.
BogsKettle depressions
Acidic sphagnum mats with tamarack, highbush blueberry, pitcher plants, and sundews.
Tallgrass prairieSandy flats and restored uplands
Big and little bluestem with blazing star and butterfly milkweed.

Trees

Black oakQuercus velutinaThe signature tree of the dune savannas, tolerant of dry sand and fire.
White oakQuercus albaA long-lived oak of older, stable dunes.
Northern red oakQuercus rubraGrows on moister slopes and forested dune ridges.
Eastern cottonwoodPopulus deltoidesA pioneer tree that survives burial by sand by sprouting new roots.
Jack pinePinus banksianaA northern pine near the southern edge of its range on the dunes.
Eastern white pinePinus strobusPersists on cool, north-facing dune slopes.
American beechFagus grandifoliaSmooth gray bark in the mature forests of sheltered ravines.
Sugar mapleAcer saccharumA late-succession tree of the richest dune forests.
American basswoodTilia americanaA fragrant-flowered tree of moist back-dune forest.
Tulip treeLiriodendron tulipiferaA tall, straight tree with tulip-shaped flowers in moist woods.
SassafrasSassafras albidumMitten-shaped leaves turn orange and red in autumn.
TamarackLarix laricinaA deciduous conifer surviving in bogs far south of its main range.

Wildflowers, shrubs & other plants

American beachgrass (marram)Ammophila breviligulataThe master dune builder, growing upward as sand buries it.
Prairie sandreedCalamovilfa longifoliaA deep-rooted grass that stabilizes foredunes.
Pitcher's thistleCirsium pitcheriA federally threatened, silvery-leaved thistle found only on Great Lakes dunes.
Common juniperJuniperus communisA northern evergreen shrub forming mats on open dunes.
BearberryArctostaphylos uva-ursiA trailing evergreen of sandy, open ground, a relic of cooler times.
Eastern prickly pearOpuntia humifusaA cactus that surprises visitors with yellow blooms in the oak savanna.
Wild lupineLupinus perennisBlue spires in late spring; the host plant of the Karner blue butterfly.
Rough blazing starLiatris asperaPurple late-summer spikes in prairies and savannas.
Butterfly milkweedAsclepias tuberosaBrilliant orange flowers feeding butterflies in sunny openings.
Purple pitcher plantSarracenia purpureaA carnivorous plant of Pinhook Bog's sphagnum mat.
Round-leaved sundewDrosera rotundifoliaTraps tiny insects on glistening, sticky hairs in bogs.
Highbush blueberryVaccinium corymbosumForms thickets in bogs and wet woods.
Skunk cabbageSymplocarpus foetidusGenerates its own heat to bloom through late-winter snow in swamps.
Little bluestemSchizachyrium scopariumA prairie bunchgrass turning coppery red in autumn.

Wildlife

42mammals
301birds
23reptiles
17amphibians
71fish

Mammals

White-tailed deerOdocoileus virginianusCommon throughout the park's woods and wetlands.
American beaverCastor canadensisReturned to reshape streams and wetlands along the Little Calumet River.
CoyoteCanis latransAn adaptable predator of dunes, prairies, and suburban edges.
Red foxVulpes vulpesHunts voles along trails and savanna edges.
RaccoonProcyon lotorForages along marshes and beaches at night.
Eastern fox squirrelSciurus nigerA large, rusty squirrel of oak savannas.
Southern flying squirrelGlaucomys volansA nocturnal glider of mature forest.
American minkMustela visonHunts along streams and marsh edges.
MuskratOndatra zibethicusBuilds lodges in the Great Marsh and other wetlands.
Eastern cottontailSylvilagus floridanusAbundant in thickets and open areas.
Northern short-tailed shrewBlarina brevicaudaA tiny predator with venomous saliva, common in leaf litter.
Eastern red batLasiurus borealisRoosts among leaves and hunts insects at dusk.

Birds

Sandhill craneGrus canadensisThousands pass over during spring and fall migration.
Great blue heronArdea herodiasStalks fish and frogs in marshes; a heron rookery along the Little Calumet River gave a park trail its name.
Bald eagleHaliaeetus leucocephalusIncreasingly seen along the lakeshore and in winter.
OspreyPandion haliaetusFishes in marshes and the lake during migration.
Red-tailed hawkButeo jamaicensisPart of the great hawk flights that follow the lakeshore in spring.
MerlinFalco columbariusA fast falcon hunting migrating songbirds along the dunes.
Piping ploverCharadrius melodusA federally listed shorebird that stops on the park's beaches during migration.
SanderlingCalidris albaChases waves along the beach in migration.
Caspian ternSterna caspiaThe largest tern, patrolling the lakeshore in summer and fall.
Cerulean warblerDendroica ceruleaA sky-blue warbler of tall, mature forest, a species of conservation concern.
Prairie warblerDendroica discolorSings a rising, buzzy song from savanna shrubs.
Yellow-breasted chatIcteria virensA noisy, secretive songbird of dense thickets.
Eastern bluebirdSialia sialisNests in open savannas and prairie edges.
Wood thrushHylocichla mustelinaIts flute-like song rings through moist forests.

Reptiles & amphibians

Eastern massasaugaSistrurus catenatusA small, threatened rattlesnake of wetlands and wet prairie; shy and rarely seen.
Blanding's turtleEmydoidea blandingiiA long-lived, yellow-chinned turtle of marshes, of conservation concern.
Common snapping turtleChelydra serpentinaA large turtle of ponds and the Great Marsh.
Eastern box turtleTerrapene carolinaA land turtle of woodlands and savannas.
Eastern hog-nosed snakeHeterodon platirhinosPlays dead when threatened; a specialist on sandy soils.
Slender glass lizardOphisaurus attenuatusA legless lizard of dry sand prairies.
Fowler's toadBufo fowleriBreeds in dune ponds and wetlands.
Blue-spotted salamanderAmbystoma lateraleA northern salamander of moist forests and wetlands.

Fish

Yellow perchPerca flavescensA popular native fish of the nearshore lake.
Chinook salmonOncorhynchus tshawytschaStocked in Lake Michigan and running up nearby streams in autumn.
Rainbow trout (steelhead)Oncorhynchus mykissLake-run trout that enter tributaries in cooler months.
Brown troutSalmo truttaA European trout stocked in the Great Lakes.
PumpkinseedLepomis gibbosusA colorful sunfish of ponds and slow water.
Round gobyNeogobius melanostomusAn invasive fish now abundant on rocky lake bottoms.
Sea lampreyPetromyzon marinusAn invasive parasite that devastated Great Lakes fisheries.

Species totals are the park's certified NPSpecies checklist (occurrence: present).

Climate & When to Visit

Indiana Dunes has a humid continental climate strongly tempered by Lake Michigan. July is the warmest month and January the coldest, with recorded extremes from 105°F in 1934 to -25°F in 1985. June is typically the wettest month. In spring and early summer, the chilly lake keeps the shoreline noticeably cooler than inland towns, and in autumn the stored warmth of the water delays the first frosts.

When cold northwesterly winds blow across the long fetch of Lake Michigan in late fall and winter, the lake pumps moisture into the air and produces lake-effect snow, sometimes dumping heavy bands on the shoreline while nearby areas stay dry. Summer brings thunderstorms that can build rapidly over the lake region, and strong onshore winds at any season raise high waves and dangerous currents.

Spring
Cool near the lake and warming inland; wildflowers bloom, and hawk and songbird migration peaks in April and May.
Summer
Warm and humid, with beach days, frequent thunderstorms, and sand hot enough to burn bare feet.
Autumn
Mild days, colorful oaks and sassafras, and sandhill crane migration; storms bring big waves.
Winter
Cold and gray, with lake-effect snow, shelf ice along the shore, and bitter wind chills.

Weather hazards

Rip currents and high waves: Lake Michigan can produce deadly currents; check the beach forecast and avoid swimming when waves are high.
Thunderstorms and lightning: Leave beaches and open dunes at the first sound of thunder.
Shelf ice: Winter ice formations along the shore can hide holes and break without warning, so never walk out on them.
Lake-effect snow squalls: Sudden bands of heavy snow can drop visibility to near zero on area highways.
Heat and hot sand: Climbing dunes in summer is strenuous; carry water and wear shoes.

Indiana Dunes Questions

When is the best time to visit Indiana Dunes National Park?

Summer is the classic beach season, while late spring and early autumn offer comfortable hiking, wildflowers, and excellent bird migration. Winter is quiet and starkly beautiful, with snow on the dunes and ice along the lake.

How does Lake Michigan affect the weather at Indiana Dunes?

The lake keeps the shore cooler in spring and summer and milder in autumn. In late fall and winter, cold winds crossing the open water produce lake-effect snow, and strong winds at any time can raise dangerous waves.

Can you climb Mount Baldy?

Access to the summit of Mount Baldy is restricted to protect visitors and the fragile dune, and entry is by ranger-guided hike. The beach trail around its base remains a popular walk.

How were the Indiana Dunes formed?

Glaciers shaped the Lake Michigan basin, and as meltwater lakes rose and fell over the last 14,000 years they left a series of beach and dune ridges. Prevailing winds continue to blow sand inland from today's beach.

Why is Indiana Dunes important to the science of ecology?

Botanist Henry Chandler Cowles studied how plant communities replace one another from beach to forest here, publishing his findings in 1899. His ideas about ecological succession became a foundation of modern ecology.

What wildlife can I see at Indiana Dunes?

More than 300 bird species have been recorded, making the park a birding hotspot during spring and fall migration. White-tailed deer, beavers, and fox squirrels are common, and the park's wetlands host frogs, turtles, and great blue herons.

More parks in the Great Plains & Midwest

← Hot Springs National Park Isle Royale National Park →

Sources: www.nps.gov · en.wikipedia.org · en.wikipedia.org · carto.nationalmap.gov · irmaservices.nps.gov · Official NPS site