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Crater Lake National Park

Oregon · Established May 22, 1902

The deepest lake in America, cradled in the ruins of a volcano

Area: 183,224 acres
Established: May 22, 1902
Recreation visits: 632,242 / yr
State: Oregon
Highest point: Mount Scott, 8,929 ft (2,722 m)
Lowest point: Southwestern park lowlands

Crater Lake Weather Forecast

Loading the National Weather Service forecast for Crater Lake…

Seven-day outlook at the park's reference point (42.941, -122.134). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of Crater Lake National Park

The Park

Crater Lake National Park, high in Oregon's Cascade Range, surrounds one of the most extraordinary bodies of water on the planet. Filling the collapsed summit of a great volcano, the lake reaches 1,949 feet at its deepest, the deepest lake in the United States, and its water is so clear and pure that sunlight turns it an intense, almost unreal shade of blue.

The mountain that stood here, Mount Mazama, blew itself apart about 7,700 years ago, and its collapse left a basin that slowly filled with rain and snowmelt. The Klamath people, whose ancestors witnessed the eruption, carry stories of it to this day. Established on May 22, 1902, Crater Lake is the fifth-oldest national park in the country, and one of the snowiest inhabited places in America.

Geography

The park sits along the crest of the southern Cascades in southwestern Oregon. At its center lies the caldera, roughly five to six miles across, with the lake's surface at 6,178 feet and rim walls rising from 7,000 to more than 8,000 feet. Wizard Island, a volcanic cone, rises from the lake's western side, while the Phantom Ship, a craggy remnant of older lava, sits near the southern shore.

Outside the rim, the land falls away through old-growth conifer forests, deep canyons carved into volcanic ash, and pumice plains. Elevations range from the lower southwest to 8,929 feet at the summit of Mount Scott, the park's highest point, on the caldera's eastern flank.

The lake has no inlets or outlets. Its level is maintained entirely by a balance between precipitation, evaporation and seepage. Streams flowing off the park's slopes feed the Rogue River to the west and the Klamath basin to the south and east.

Landmarks

Crater LakeLake · 6,178 ftA caldera lake of astonishing clarity and color, fed only by rain and snow.
Wizard IslandIsland · 6,933 ftA cinder cone that erupted from the caldera floor after the collapse and still has a summit crater.
Phantom ShipIslandA jagged island of ancient volcanic rock that resembles a ghostly sailing ship.
Mount ScottPeak · 8,929 ftThe park's highest summit, an older volcanic cone topped by a fire lookout.
Hillman PeakPeak · 8,151 ftThe highest point on the caldera rim, a volcano sliced in half by the collapse.
The WatchmanPeakA rim peak with a historic lookout and a panoramic view of Wizard Island.
Llao RockPeakA massive cliff of dark lava rising about 1,800 feet above the lake.
Garfield PeakPeakA popular summit trail from Rim Village with wildflowers and sweeping lake views.
Cleetwood CoveCoastThe only legal access to the lakeshore, via a steep switchbacking trail.
Sun NotchAreaA glacially carved notch in the rim with the best view of the Phantom Ship.
The PinnaclesAreaTall spires of welded pumice and ash, marking fossil gas vents from the eruption.
Pumice DesertAreaA barren plain buried under deep pumice and ash, still sparsely vegetated thousands of years later.
Union PeakPeakThe eroded volcanic plug of an extinct shield volcano in the park's southwest.
Rim VillageAreaThe historic heart of the park, with Crater Lake Lodge perched on the caldera edge.

Geology

Crater Lake is a child of subduction. Off the Pacific Northwest coast, the Juan de Fuca plate slides beneath North America, and the melting it triggers at depth feeds the volcanoes of the Cascade Range. Mount Mazama was one of them: a cluster of overlapping volcanoes that grew over roughly 420,000 years, building layers of andesite, dacite and rhyodacite lava and ash. At its peak it probably stood somewhere between 10,800 and 12,100 feet high, and glaciers repeatedly carved its flanks.

About 7,700 years ago, Mazama's magma chamber began a series of eruptions. Thick lava flows of rhyodacite, including those that form Llao Rock and the Cleetwood flow, oozed out first. Then came the climactic eruption, one of the largest in North America during the last several hundred thousand years. A towering column of pumice and ash spread debris over eight states and parts of Canada, and glowing avalanches of hot ash, called pyroclastic flows, raced down the mountain's slopes, filling valleys to depths of hundreds of feet.

With its magma chamber emptied, the summit collapsed into the void, forming a caldera about 4,000 feet deep. Within a few centuries, smaller eruptions built Wizard Island, the submerged Merriam Cone and a lava platform on the caldera floor. Meanwhile, rain and snowmelt began to fill the basin, and the lake reached roughly its present level within several centuries, when inflow balanced evaporation and seepage.

The eruption's traces are everywhere. The Pinnacles in Wheeler and Sand creeks are hardened fossil gas vents, or fumaroles, that rose through still-hot ash deposits. The Pumice Desert remains a plain where plants struggle to grow in porous volcanic debris. Hydrothermal springs still seep into the lake bottom, a sign that the volcanic system has not entirely gone quiet.

Deep time

About 420,000 years agoVolcanic activity builds the first cones of the Mount Mazama complex.
Pleistocene ice agesGlaciers repeatedly carve U-shaped valleys into Mazama's flanks, later seen as notches in the caldera rim.
Shortly before 7,700 years agoRhyodacite lava flows erupt on the north side, forming Llao Rock and the Cleetwood flow.
About 7,700 years agoMazama's climactic eruption spews ash across the Northwest and the summit collapses into a caldera.
Within a few centuries after collapseEruptions on the caldera floor build Wizard Island, Merriam Cone and a central lava platform as the lake begins to fill.
About 4,800 years agoA small underwater dome erupts on the flank of Wizard Island, the most recent known eruption at Crater Lake.

The rocks

Mount Mazama volcanic complexPleistocene to Holocene
Stacked andesite and dacite lavas and ash exposed in the caldera walls.
Climactic pumice and ignimbrite depositsHolocene, about 7,700 years
Rhyodacite pumice and welded ash that blanket the park and fill surrounding valleys.
Llao Rock lava flowHolocene
A thick rhyodacite flow that filled an older glacial valley just before the collapse.
Wizard Island cinder coneHolocene
An andesite cinder cone that rises about 755 feet above the lake.
Merriam ConeHolocene
A submerged volcanic cone rising about 1,300 feet above the caldera floor.
Mount ScottPleistocene
An older andesitic cone on Mazama's eastern flank and the park's highest peak.
The PinnaclesHolocene
Erosion-resistant spires of ash cemented around gas vents in pyroclastic flow deposits.

Trees, Plants & Ecosystems

822vascular plant species recorded

Deep caldera lake6,178 ft surface to 1,949 ft deep
An extremely clear, nutrient-poor lake with moss beds at depth and introduced kokanee and rainbow trout.
Mixed conifer forestAbout 4,000–6,000 ft
Ponderosa and sugar pine, white fir and Douglas-fir on the lower slopes.
Lodgepole pine forestPumice plains, about 5,000–6,500 ft
Lodgepole pines tolerate the porous, nutrient-poor pumice soils.
Mountain hemlock and red fir forestAbout 6,000–7,500 ft
Deep-snow forests that dominate the area around the caldera rim.
Subalpine rim and meadowsAbout 7,000–8,900 ft
Whitebark pine, wind-sculpted trees and summer wildflower meadows along the rim and peaks.

Trees

Mountain hemlockTsuga mertensianaThe dominant tree near the rim, its drooping tops shed heavy snow.
Whitebark pinePinus albicaulisA wind-battered pine of the high rim, now declining due to blister rust and beetles.
Shasta red firAbies magnificaA handsome, deep-snow fir forming dense stands just below the rim.
Lodgepole pinePinus contortaColonizes the pumice plains, including the edge of the Pumice Desert.
Ponderosa pinePinus ponderosaTall, orange-barked pines in the lower, drier parts of the park.
Sugar pinePinus lambertianaThe world's tallest pine, bearing cones up to a foot and a half long.
White firAbies concolorA shade-tolerant fir of the park's mixed forests.
Subalpine firAbies lasiocarpaA narrow, spire-shaped fir of cold high-elevation sites.
Douglas-firPseudotsuga menziesiiGrows in the lower western canyons of the park.
Western white pinePinus monticolaA slender five-needle pine with long, curved cones.

Wildflowers, shrubs & other plants

Scarlet paintbrushCastilleja miniataRed flower bracts that brighten summer meadows along the rim.
Crimson columbineAquilegia formosaNodding red and yellow flowers loved by hummingbirds.
Lewis's monkeyflowerErythranthe lewisiiPink flowers lining the banks of cold mountain streams.
Spreading phloxPhlox diffusaLow mats of pink and white blossoms on rocky pumice slopes.
Marum-leaved buckwheatEriogonum marifoliumA ground-hugging buckwheat of open pumice fields.
Cliff penstemonPenstemon rupicolaRose-purple flowers spilling from rocky crevices on the rim.
PussypawsCalyptridium umbellatumFuzzy pink flower clusters spreading across bare pumice.
BeargrassXerophyllum tenaxTall stalks of creamy blossoms rising from grassy clumps.
Green corn lilyVeratrum virideLarge pleated leaves in wet meadows, toxic to livestock.
Columbian monkshoodAconitum columbianumHooded purple flowers along streams in late summer.
Elephant's headPedicularis groenlandicaPink flowers shaped like tiny elephant heads in boggy meadows.
Pinemat manzanitaArctostaphylos nevadensisA creeping evergreen shrub of the forest floor.
Thin-leaved huckleberryVaccinium membranaceumIts sweet berries feed black bears in late summer.
PinedropsPterospora andromedeaA reddish, leafless plant that draws its nourishment from fungi.

Wildlife

68mammals
150birds
3reptiles
8amphibians
6fish

Mammals

American black bearUrsus americanusRoams the forests and meadows, especially in summer and fall.
ElkCervus elaphusHerds graze the park's meadows and forest openings in summer.
Mule deerOdocoileus hemionusCommonly seen along roads and meadows in summer.
Mountain lionPuma concolorAn elusive predator that follows deer and elk.
Pacific martenMartes americanaA sleek weasel of old-growth forests, active year-round beneath the snow.
American pikaOchotona princepsSqueaks from talus slopes along the rim.
Golden-mantled ground squirrelCallospermophilus lateralisA familiar striped squirrel at rim overlooks.
Yellow-pine chipmunkTamias amoenusScampers through forests and rocky slopes in summer.
Yellow-bellied marmotMarmota flaviventrisBasks on rocks near the rim.
Snowshoe hareLepus americanusTurns white in winter to blend into the snowy forest.
Red foxVulpes vulpesThe high-mountain Cascade red fox is occasionally seen in winter.
Douglas squirrelTamiasciurus douglasiiA noisy tree squirrel that stores conifer cones.
North American porcupineErethizon dorsatumFeeds on the inner bark of conifers.

Birds

Clark's nutcrackerNucifraga columbianaCaches thousands of whitebark pine seeds, planting new trees in the process.
Canada jayPerisoreus canadensisA bold, fluffy gray jay that visits picnic areas.
Steller's jayCyanocitta stelleriA crested blue jay of the conifer forests.
Mountain chickadeePoecile gambeliA white-browed chickadee common in rim forests.
Bald eagleHaliaeetus leucocephalusOccasionally hunts fish on the lake.
Peregrine falconFalco peregrinusNests on caldera cliffs, one of the park's success stories.
OspreyPandion haliaetusDives for fish in the lake during summer.
Northern spotted owlStrix occidentalisA threatened owl of the park's old-growth forests.
Sooty grouseDendragapus obscurusMales hoot deeply from conifer branches in spring.
Black-backed woodpeckerPicoides arcticusSeeks out burned forests to feed on wood-boring beetles.
Red-breasted nuthatchSitta canadensisCreeps headfirst down tree trunks in search of insects.
Red crossbillLoxia curvirostraIts crossed bill pries seeds from conifer cones.
Rufous hummingbirdSelasphorus rufusVisits wildflower meadows on its late-summer migration.
Townsend's solitaireMyadestes townsendiA gray thrush that sings from treetops near the rim.

Reptiles & amphibians

Rough-skinned newtTaricha granulosaA distinctive Crater Lake subspecies, the Mazama newt, lived in the lake but has declined sharply since introduced crayfish spread.
Cascades frogRana cascadaeA mountain frog of wet meadows and ponds.
Western toadAnaxyrus boreasBreeds in shallow ponds and wetlands.
Pacific treefrogPseudacris regillaA small frog with a loud chorus in spring meadows.
Long-toed salamanderAmbystoma macrodactylumEmerges from snowmelt pools in late spring.
Coastal tailed frogAscaphus trueiLives in cold, fast-flowing streams.
Sagebrush lizardSceloporus graciosusOne of only a few reptiles hardy enough for the park's short summers.
Pygmy short-horned lizardPhrynosoma douglasiiA small, flattened lizard of sunny pumice flats.

Fish

Kokanee salmonOncorhynchus nerkaA landlocked sockeye introduced to the naturally fishless lake.
Rainbow troutOncorhynchus mykissStocked in the lake between 1888 and 1941 and still reproduces there.
Bull troutSalvelinus confluentusA threatened native char restored to Sun Creek in the park.

Insects & other invertebrates

Western tiger swallowtailPapilio rutulusGlides through summer meadows and roadsides.
Mourning cloakNymphalis antiopaOne of the first butterflies active in spring.

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

Climate & When to Visit

Crater Lake's climate is dominated by snow. Winter storms from the Pacific slam into the Cascade crest, and the park headquarters averages about 41 feet of snow a year, with snowpack commonly lasting into July. The rim is often wrapped in clouds during storms, and the lake is completely hidden roughly half the time in winter.

Summers are short, cool and generally dry and sunny. July, August and September offer the most reliable warm weather, though afternoon thunderstorms occasionally form and nights are chilly at rim elevations. The lake itself rarely freezes over completely because it holds so much stored heat.

Spring
Snow still buries the high country; Rim Drive remains closed and sunny days alternate with fresh storms.
Summer
Rim Drive, trails and boat tours open, usually by July, with wildflowers blooming as snow melts and warm, dry days.
Autumn
Crisp days and clear skies in September give way to the first snow in October.
Winter
Deep snow closes most roads; the south entrance and Rim Village stay open for snowshoeing and skiing.

Weather hazards

Deep snow and avalanches: Avalanche danger exists on steep slopes, and snow cornices form along the rim; stay back from the edge.
Caldera cliffs: Caldera walls are steep and unstable; only descend to the water on the Cleetwood Cove Trail.
Cold water: The lake stays very cold even in summer, so swimmers can quickly become hypothermic.
Road closures: Rim Drive and the north entrance close for much of the year; check road status before visiting.
Lightning: Summer thunderstorms can bring lightning to exposed peaks such as Mount Scott and the Watchman.

Crater Lake Questions

When is the best time to visit Crater Lake?

Mid-July through mid-September is best, when roads, trails and boat tours are usually open and the weather is typically warm and dry. Winter is beautiful but most of the park is buried under snow.

Why is Crater Lake so blue?

The lake is extremely deep and very clear, with few particles or algae. Water absorbs the longer red and green wavelengths of sunlight, leaving mostly blue light to scatter back to our eyes.

How much snow does Crater Lake get?

Park headquarters averages about 41 feet of snow per year, and snow often lingers into early summer. It is one of the snowiest places in the United States where people live year-round.

How was Crater Lake formed?

About 7,700 years ago, Mount Mazama erupted so violently that its summit collapsed into the emptied magma chamber, forming a caldera. Rain and snowmelt then filled the basin over several centuries.

Can you swim in Crater Lake?

Yes, swimming is allowed at Cleetwood Cove and Wizard Island when they are accessible. The water is very cold, and the steep Cleetwood Cove Trail is the only way down to the shore.

Are there fish in Crater Lake?

The lake had no native fish. Kokanee salmon and rainbow trout, stocked between 1888 and 1941, still survive there, and fishing is allowed without a license to help reduce their numbers.

More parks in the Pacific West

← Congaree National Park Cuyahoga Valley National Park →

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