Katmai National Park & Preserve

Alaska · Established December 2, 1980

Brown bears, salmon, and a valley buried by the 20th century's greatest eruption

Area: 3,674,529 acres
Established: December 2, 1980
Recreation visits: 34,479 / yr
State: Alaska
Highest point: Mount Denison, 7,606 ft (2,318 m)
Lowest point: Sea level along Shelikof Strait

Katmai Weather Forecast

Loading the National Weather Service forecast for Katmai…

Seven-day outlook at the park's reference point (58.622, -155.013). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of Katmai National Park & Preserve

The Park

In June 1912, the ground on the Alaska Peninsula split open at a place later named Novarupta and unleashed the largest volcanic eruption of the 20th century. Over about 60 hours it buried a green valley under hundreds of feet of glowing ash, and when explorers arrived four years later they found the deposit still venting thousands of steaming fumaroles. They named it the Valley of Ten Thousand Smokes, and Katmai National Monument was created in 1918 to protect it.

Today Katmai is equally renowned for life. The park and preserve hold one of the world's largest protected populations of brown bears, drawn each summer to rivers crowded with sockeye salmon. At Brooks Falls, bears stand in the white water and catch leaping fish, a scene watched by visitors on platforms and by millions online. Beyond lie volcanoes, glacier-scoured lakes, tundra, and a wild, storm-lashed coast on Shelikof Strait.

Geography

Katmai National Park and Preserve covers more than four million acres at the northern end of the Alaska Peninsula, across Shelikof Strait from Kodiak Island. The Aleutian Range runs through the park like a crest of ice and fire, separating a rugged, fjord-cut Pacific coast to the east from a land of large lakes, rivers, and rolling tundra draining west toward Bristol Bay.

West of the mountains, huge glacially carved lakes, including Naknek Lake, Brooks Lake, and Lake Grosvenor, feed the Naknek River system and some of the world's richest sockeye salmon runs. Brooks Camp, on a short river linking Brooks Lake to Naknek Lake, is the park's best-known destination. There are no roads into the park; visitors arrive by floatplane or boat, typically from King Salmon.

The volcanic heart of the park lies along the range crest, where Mount Katmai, Trident, Mageik, Martin, Griggs, and Novarupta cluster around the head of the Valley of Ten Thousand Smokes. Farther east, glaciated peaks such as Mount Denison and Snowy Mountain rise above the Pacific coast, where bays like Hallo Bay and Kukak Bay attract bears to sedge meadows and clam flats.

Landmarks

NovaruptaVolcanoThe vent of the 1912 eruption, now plugged by a lava dome about 295 feet high.
Mount KatmaiVolcanoA stratovolcano whose summit collapsed in 1912 as magma drained toward Novarupta, leaving a caldera now holding a lake.
Valley of Ten Thousand SmokesValleyA 40-square-mile ash-flow sheet up to 700 feet thick, now being carved into slot canyons by rivers.
Trident VolcanoVolcanoA cluster of volcanic cones near Novarupta that erupted between 1953 and 1974.
Mount MageikVolcanoAn ice-covered volcano with a steaming summit crater lake.
Mount MartinVolcanoA frequently steaming stratovolcano at the southwest end of the Katmai cluster.
Mount GriggsVolcanoA large volcano with active fumaroles, named for explorer Robert Griggs.
Mount DenisonPeak · 7,606 ftThe highest point in the park, a heavily glaciated and remote summit.
Snowy MountainVolcanoA glacier-mantled volcano in the park's remote eastern mountains.
Mount KukakVolcanoAn ice-clad stratovolcano above the Shelikof Strait coast.
Fourpeaked MountainVolcanoA glaciated volcano that surprised scientists with a steam-driven eruption in 2006.
Brooks FallsWaterfallA roughly 6-foot falls where brown bears gather to catch leaping sockeye salmon.
Brooks RiverRiverA short river linking Brooks Lake and Naknek Lake, site of Brooks Camp and thousands of years of human history.
Naknek LakeLakeThe park's largest lake, a vast glacier-carved basin draining to Bristol Bay.
Hallo BayCoastA coastal meadow and tideflat on Shelikof Strait known for bear viewing.
Kukak BayCoastA deep bay on the park's Pacific coast backed by glaciated mountains.

Geology

Katmai sits above one of the most active subduction zones on Earth. Along the Aleutian Trench, the Pacific Plate dives beneath the North American Plate, and as it sinks, water released from the descending slab melts the mantle above it. The resulting magma rises to build the chain of stratovolcanoes that forms the Aleutian Range. Well over a dozen volcanoes lie within the park, several active in historic times.

The volcanoes grew on older rocks, including Jurassic marine sandstones and siltstones of the Naknek Formation, packed with fossils of ammonites and clams. During the Pleistocene, great glaciers flowed from the range, gouging the deep basins of Naknek, Brooks, and Grosvenor lakes and leaving moraines across the western lowlands. Glaciers still cap the high peaks.

On June 6, 1912, an eruption began at Novarupta that lasted about 60 hours and expelled roughly 13 to 15 cubic kilometers of magma, some thirty times the volume of Mount St. Helens in 1980. Pyroclastic flows raced down the valley of the Ukak River, filling it with ash-flow tuff up to about 700 feet deep, while ash fell across Kodiak and beyond. Because the magma chamber that fed Novarupta lay partly beneath Mount Katmai, six miles away, Katmai's summit collapsed into a caldera about 2,000 feet deep.

When botanist Robert Griggs led National Geographic Society expeditions into the valley in 1916, the hot deposit was still steaming through countless fumaroles. The vents have long since cooled, and rivers are now cutting narrow gorges into the pale tuff, revealing a cross-section of one of the great eruptions of the modern era.

Deep time

Jurassic, about 160–145 million years agoMarine sediments of the Naknek Formation accumulate along the continental margin.
Last several million yearsSubduction of the Pacific Plate builds the volcanoes of the Aleutian Range.
Pleistocene Ice AgeGlaciers carve the deep basins of Naknek, Brooks, and Grosvenor lakes.
About 9,000 years agoPeople begin living along the Brooks River, beginning a long record of human history.
June 6–8, 1912Novarupta erupts for about 60 hours, filling the Valley of Ten Thousand Smokes and collapsing Mount Katmai's summit.
1916–1918Robert Griggs explores and names the valley, and Katmai National Monument is established.
1953–1974Trident Volcano erupts, building a new cone near Novarupta.

The rocks

Valley of Ten Thousand Smokes ash-flow tuff1912
A pale, welded-to-loose pyroclastic deposit up to about 700 ft thick.
Novarupta lava dome1912
A rubbly plug of rhyolite about 295 ft high and 1,180 ft wide sealing the 1912 vent.
Mount Katmai caldera1912
A collapse caldera roughly 2 by 2.5 miles across, now filled partly by a lake.
Naknek FormationLate Jurassic
Fossil-rich marine sandstone and siltstone underlying much of the region.
Aleutian arc stratovolcanoesPleistocene to present
Layered cones of andesite and dacite lava and ash, including Katmai, Mageik, Martin, and Griggs.
Glacial moraines and lake basinsPleistocene
Ridges of till and deep troughs left by the ice sheets west of the range.

Trees, Plants & Ecosystems

535vascular plant species recorded

Coastal meadows and tidal flatsSea level–200 ft
Sedge meadows and clam-rich flats along Shelikof Strait where bears graze in early summer.
Boreal forest and lake shoresAbout 50–1,000 ft
White spruce, paper birch, and balsam poplar ring the western lakes and rivers.
Alder and willow shrublandAbout 500–2,500 ft
Dense thickets on slopes and stream corridors, prime bear habitat.
TundraAbout 1,500–4,000 ft
Low heaths of crowberry, lingonberry, and dwarf birch with lichens and wildflowers.
Volcanic barrens and glaciersAbove about 3,000 ft
Ash deserts, lava, and ice fields where plants are only beginning to colonize the 1912 deposits.
Salmon rivers and lakesFreshwater
Cold, clear waters where millions of sockeye salmon return to spawn, feeding bears, eagles, and forests alike.

Trees

White sprucePicea glaucaThe dominant conifer of forests around the western lakes.
Sitka sprucePicea sitchensisGrows along the moist Pacific coast of the park.
Paper birchBetula papyriferaMixes with spruce in the lowland forests around Brooks Camp.
Resin birchBetula neoalaskanaAn Alaska birch of interior-type forests and bogs.
Kenai birchBetula kenaicaA small birch of south-central Alaska found on slopes and forest edges.
Balsam poplarPopulus balsamiferaA fragrant cottonwood of river bars and floodplains.
Sitka alderAlnus viridisForms nearly impenetrable thickets on mountain slopes.
Feltleaf willowSalix alaxensisA tall willow of gravel bars, browsed by moose.
Sitka mountain ashSorbus sitchensisA shrubby tree with red berries eaten by birds and bears.

Wildflowers, shrubs & other plants

FireweedChamerion angustifoliumMagenta spires that bloom from the bottom up as summer progresses.
Nootka lupineLupinus nootkatensisBlue-purple lupines brighten coastal meadows and roadsides.
Cow parsnipHeracleum maximumA towering, white-flowered plant eaten by bears in early summer.
Wild irisIris setosaPurple irises fill wet coastal meadows in June and July.
Chocolate lilyFritillaria camschatcensisDark, bell-shaped flowers of coastal meadows, with bulbs once used as food.
MonkshoodAconitum delphiniifoliumBeautiful but highly poisonous deep-blue flowers.
SalmonberryRubus spectabilisOrange to red berries ripen along coastal thickets.
Devil's clubOplopanax horridusA spiny shrub of wet, shaded forest.
CrowberryEmpetrum nigrumA mat-forming tundra shrub with black berries.
LingonberryVaccinium vitis-idaeaTart red berries on evergreen tundra mats.
Bog blueberryVaccinium uliginosumA key late-summer food for bears and birds.
Eightpetal mountain-avensDryas octopetalaA white-flowered pioneer of gravel and alpine tundra.
Bluejoint reedgrassCalamagrostis canadensisA tall grass of wet meadows and open lowlands.
Beach ryegrassLeymus mollisBinds sand and gravel along the coast.

Wildlife

35mammals
160birds
1amphibians
31fish

Mammals

Brown bearUrsus arctosAn estimated 2,200 bears live in the park and preserve, fattening on salmon before winter denning.
MooseAlces alcesBrowses willow along lakes and rivers.
Gray wolfCanis lupusPacks roam the lowlands, occasionally seen near Brooks Camp.
CaribouRangifer tarandusMembers of the Northern Alaska Peninsula herd use the western tundra.
Red foxVulpes vulpesHunts voles and ground squirrels across tundra and shoreline.
Canada lynxLynx canadensisA secretive cat of the spruce forest.
WolverineGulo guloA rare, far-ranging scavenger of the mountains.
North American river otterLontra canadensisFishes in lakes, rivers, and coastal waters.
American beaverCastor canadensisDams streams in the lowland forests.
Snowshoe hareLepus americanusTurns white in winter; a staple of lynx.
Arctic ground squirrelSpermophilus parryiiChirps from burrows in tundra and meadows.
Sea otterEnhydra lutrisFloats in kelp and bays along Shelikof Strait.
Steller sea lionEumetopias jubatusHauls out on rocky islets off the coast.
Harbor sealPhoca vitulinaCommon in coastal bays and river mouths.

Birds

Bald eagleHaliaeetus leucocephalusGathers along salmon streams and nests on the coast.
Golden eagleAquila chrysaetosHunts ground squirrels over tundra and mountains.
Tufted puffinFratercula cirrhataNests on coastal cliffs and islands.
Horned puffinFratercula corniculataNests in rock crevices along the Pacific coast.
Glaucous-winged gullLarus glaucescensScavenges salmon along rivers and beaches.
Harlequin duckHistrionicus histrionicusA boldly patterned duck of rushing streams and rocky coasts.
Barrow's goldeneyeBucephala islandicaA diving duck of lakes and bays.
Common loonGavia immerCalls across the large western lakes in summer.
Tundra swanCygnus columbianusNests in wetlands of the western lowlands.
Willow ptarmiganLagopus lagopusAlaska's state bird, white in winter and mottled brown in summer.
American dipperCinclus mexicanusWalks underwater in fast streams to feed.
Golden-crowned sparrowZonotrichia atricapillaSings a plaintive, descending song from alder thickets.
Common ravenCorvus coraxClever and ever-present, from coast to volcano.
Sandhill craneGrus canadensisMigrates through and nests in wet tundra.

Reptiles & amphibians

Wood frogRana sylvaticaThe park's only amphibian, and no reptiles occur here; it survives winter partly frozen.

Fish

Sockeye salmonOncorhynchus nerkaReturns by the millions to the Naknek system, the foundation of Katmai's food web.
Chinook salmonOncorhynchus tshawytschaThe largest Pacific salmon, spawning in larger rivers.
Coho salmonOncorhynchus kisutchRuns late in summer and fall.
Pink salmonOncorhynchus gorbuschaAbundant in short coastal streams on the Pacific side.
Chum salmonOncorhynchus ketaSpawns in coastal rivers and feeds bears in late summer.
Rainbow troutOncorhynchus mykissLarge native rainbows follow salmon runs to feed on eggs.
Dolly VardenSalvelinus malmaA char of streams and lakes.
Arctic charSalvelinus alpinusA cold-water char of deep lakes.
Lake troutSalvelinus namaycushInhabits the park's large, deep lakes.
Arctic graylingThymallus arcticusRecognized by its sail-like dorsal fin.
Northern pikeEsox luciusLurks in weedy lakes of the western lowlands.
Threespine sticklebackGasterosteus aculeatusA small, spiny fish that feeds salmon fry and birds.

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

Climate & When to Visit

Katmai lies between the stormy North Pacific and the Bering Sea, and the Aleutian Range stands in the path of the weather systems that march between them. Cool, wet, cloudy conditions dominate spring, summer, and fall, and weather can change within hours. The Pacific coast is wetter and windier than the western lakes region, where Brooks Camp sees somewhat more sunshine and summer highs mostly in the 50s and 60s°F.

Strong winds are a hallmark of the park, funneled through mountain passes and across the large lakes, where they can raise dangerous waves. In the Valley of Ten Thousand Smokes, winds sometimes lift old volcanic ash into dust storms. Winters are colder and drier, with snow across the mountains and ice on the lakes.

Spring
Late and cool, with snow lingering at elevation into June; bears emerge and graze on coastal sedges.
Summer
Mild, damp, and changeable, with long daylight; July is the peak for bears fishing at Brooks Falls.
Autumn
Rain and wind increase, tundra turns red and gold, and bears return to the Brooks River in September to fatten on spawned-out salmon.
Winter
Cold, dark, and snowy; lakes freeze, bears den, and visitor services are closed.

Weather hazards

Brown bears: Follow Brooks Camp's bear rules, keep at least 50 yards from bears, and never approach or leave food unattended.
Wind and waves: Sudden winds on Naknek Lake and other large lakes can swamp small boats; stay close to shore.
Weather flight delays: Floatplanes cannot fly in low clouds or high wind, so build extra days into your trip.
Hypothermia: Cold rain and wind can chill hikers even in summer, so carry waterproof layers.
River crossings: Glacial and ash-laden rivers, especially in the Valley of Ten Thousand Smokes, are cold, swift, and deceptive.

Katmai Questions

When is the best time to see bears at Brooks Falls?

July is usually the peak, when sockeye salmon leap the falls and dozens of bears may gather over a day. Bears return in September to feed on spawned-out salmon along the river. Late June and August typically have fewer bears at the falls.

What is the weather like in Katmai National Park?

Expect cool, wet, windy, and changeable weather during the summer season, with highs mostly in the 50s and 60s°F at Brooks Camp. Bring rain gear and warm layers, and plan for flight delays caused by fog and wind.

What created the Valley of Ten Thousand Smokes?

The 1912 eruption of Novarupta, the largest of the 20th century, sent pyroclastic flows that filled the valley with ash up to about 700 feet deep. Steam from buried streams and ice escaped through thousands of fumaroles, which inspired the name when Robert Griggs arrived in 1916.

How do you get to Katmai National Park?

No roads reach the park. Most visitors fly commercially to King Salmon and then take a floatplane to Brooks Camp, or join air taxi or boat trips to the coast for bear viewing.

How many brown bears live in Katmai?

About 2,200 brown bears live in Katmai National Park and Preserve, one of the largest protected brown bear populations in the world. Their abundance depends on the enormous salmon runs of the Bristol Bay region.

Are Katmai's volcanoes still active?

Yes. The park lies on the Aleutian volcanic arc and contains many volcanoes, several of which have erupted or steamed in the past century. The USGS Alaska Volcano Observatory monitors them.

More parks in the Alaska

← Joshua Tree National Park Kenai Fjords National Park →

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