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The Wallowa Mountains () are a mountain range located in the
Columbia Plateau The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Col ...
of northeastern
Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. The range runs approximately northwest to southeast in southwestern
Wallowa County Wallowa County () is the northeastern most county in the U.S. state of Oregon. As of the 2020 census, the population was 7,391, making it Oregon's fifth-least populous county. Its county seat is Enterprise. According to '' Oregon Geographic Nam ...
and eastern Union County between the Blue Mountains to the west and the
Snake River The Snake River is a major river of the greater Pacific Northwest region in the United States. At long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake ...
to the east. The range is sometimes considered to be an eastern spur of the Blue Mountains, and it is known as the "
Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...
of Oregon". Much of the range is designated as the Eagle Cap Wilderness, part of the
Wallowa–Whitman National Forest The Wallowa–Whitman National Forest is a United States National Forest in the U.S. states of Oregon and Idaho. Formed upon the merger of the Wallowa and Whitman national forests in 1954, it is located in the northeastern corner of the state, in ...
.


Geography

The range is drained by the
Wallowa River The Wallowa River is a tributary of the Grande Ronde River, approximately long, in northeastern Oregon in the United States. It drains a valley on the Columbia Plateau in the northeast corner of the state north of Wallowa Mountains. The Wallowa ...
, which flows from the north side of the mountains, and its tributary the Minam River, which flows through the west side of the range. The
Imnaha River The Imnaha River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed May 3, 2011 tributary of the Snake River in the U.S. state of Oregon. Flowing generally east near the headwaters a ...
flows from the east side of the range. The highest point in the range is Sacajawea Peak, which is above sea level. Sacajawea is the sixth highest mountain in Oregon and the state's highest peak outside of the
Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...
.


Geology

Many
geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
s believe that the Wallowa Mountains in northeastern Oregon are a displaced fragment of the
Insular Belt The Insular Belt is a physical geography, physiogeological region on the north western North American coast. It consists of three major island groups and many smaller islands and stretches from southern British Columbia into Alaska and the Yukon. I ...
. The core of the Wallowas is composed of the Wallowa Batholith surrounded by
Columbia River basalt The Columbia River Basalt Group is the youngest, smallest and one of the best-preserved continental large igneous province, flood basalt province on Earth, covering over mainly eastern Oregon and Washington (state), Washington, western Idaho, a ...
. In addition there are many older
terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust (geology), crust fragment formed on a tectonic plate (or broken off from it) and Accretion (geology), accreted or "Suture (geology), sutured" to crust lying on another pla ...
s between the batholith and basalt flows. The Wallowa Batholith is formed of
granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies under ...
from a
magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
upwelling in
Late Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...
and
Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145  Ma to 100.5 Ma. Geology Pro ...
time (between 160 million and 120 million years ago). The placement of this rock caused uplift of the surface, which at the time was tropical sea. This is evident from the
slate Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. ...
,
quartzite Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tec ...
, and
marble Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or Dolomite (mineral), dolomite. Marble is typically not Foliation (geology), foliated (layered), although there are exceptions. In geology, the ...
present in the mountains, which come from
metamorphism Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of ch ...
of the
sedimentary Sedimentary rocks are types of rock (geology), rock that are formed by the accumulation or deposition of mineral or organic matter, organic particles at Earth#Surface, Earth's surface, followed by cementation (geology), cementation. Sedimentati ...
deposits of oceans during the
Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
. At the center of the Batholith are granodioritic rocks, while the outer limits of the range are tonalitic. The granite batholith is cut by
dikes Dyke (UK) or dike (US) may refer to: General uses * Dyke (slang), a slang word meaning "lesbian" * Dike (geology), a subvertical sheet-like intrusion of magma or sediment * Dike (mythology), ''Dikē'', the Greek goddess of moral justice * Dikes ...
; however, these are uncommon.
Glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
s carved out the valleys during the late
Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
, which left a number of moraines. The series of moraines is formed by a series of glacial advances and retreats.
Glacial till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...
is also a common feature of the valleys. The melting of the glaciers produced a large quantity of water, which carried sediment to the valley bottoms, leaving delta deposits on top of the former deposits.


Climate

In the mountains, much
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
falls as
snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...
. Total snowfall peaks around March. Most precipitation in the area is
orographic precipitation Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as ''oreography'', ''orology'' or ''oreology'') falls within the broader discip ...
. Near the tops of the mountains, total annual precipitation can exceed per year, while in the valleys it can be as low as .


Avalanches

The Wallowa Mountains are a popular destination for backcountry skiers and snowmobilers. However, avalanches are a consistent threat to backcountry skiers and snowmobilers. In February 2014, two backcountry skiers were killed and two others were serious injured in the southern Wallowas on
Cornucopia Peak Cornucopia Peak is a mountain summit located in Baker County, Oregon, US. Description Cornucopia Peak is located in the southern Wallowa Mountains and is set along the boundary of the Eagle Cap Wilderness on land managed by Wallowa–Whitma ...
when an avalanche swept into a mountainside gully. On March 8, 2016, the local avalanche center director, Kip Rand, was killed backcountry skiing near the Hurwal Divide and
Chief Joseph Mountain Chief Joseph Mountain is a mountain summit located in Wallowa County, Oregon, Wallowa County, Oregon, US. Description Chief Joseph Mountain is located five miles south of Joseph, Oregon, in the Wallowa Mountains. It is set within the Eagle Ca ...
in an avalanche following the collapse of a large cornice.


Ecology

The higher precipitation of the mountains compared with the surrounding country has created a
mesic habitat In ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie. Mesic habitats transition to xeric shrublands in a non-linear fashion, ...
in the Wallowas. Vegetation in the region contains combinations of plants found in both the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...
and the Cascades. At low elevations, Douglas fir is the most common tree for slopes, whereas
Engelmann spruce ''Picea engelmannii'', with the common names Engelmann spruce, white spruce, mountain spruce, and silver spruce, is a species of spruce native to western North America. It is mostly a high-altitude mountain tree but also appears in watered canyon ...
and
lodgepole pine ''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, ...
occur in valley bottoms, with
grand fir ''Abies grandis'' (grand fir, giant fir, lowland white fir, great silver fir, western white fir, Vancouver fir, or Oregon fir) is a fir native to the Pacific Northwest and Northern California of North America, occurring at altitudes of sea leve ...
common below . In meadows and around springs and seeps,
willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
s and
sedge The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...
grow. Above ,
subalpine fir ''Abies lasiocarpa'', the subalpine fir or Rocky Mountain fir, is a western North American fir tree. Description ''Abies lasiocarpa'' is a medium-sized evergreen conifer with a very narrow conic crown, growing to tall, exceptionally , with a t ...
is dominant, and
whitebark pine ''Pinus albicaulis'', known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine ...
is often found on ridges and south-facing slopes.


Human history

The area was home to the Wallowa band of the Lower
Nez Perce The Nez Percé (; autonym in Nez Perce language: , meaning "we, the people") are an Indigenous people of the Plateau who are presumed to have lived on the Columbia River Plateau in the Pacific Northwest region for at least 11,500 years.Ames, K ...
. The Nez Perce lived in the canyons and burned trees to create meadows for the horses that they obtained around 1730. In 1834, Captain Bonneville crossed through the mountains and met with the lower Nez Perce on his way to
Fort Walla Walla Fort Walla Walla is a United States Army fort located in Walla Walla, Washington. The first Fort Walla Walla was established July 1856, by Lieutenant Colonel Edward Steptoe, 9th Infantry Regiment. A second Fort Walla Walla was occupied Septem ...
. In the 1840s, people began to move west, bringing settlers through the land. The Nez Perce began to trade with these settlers. A settlement in the mountains was built in 1861. In 1863, a new treaty was signed that relinquished lands that granted by an 1855 treaty, turning them over to the American government. This same year, the settlers in the mountains moved to present-day La Grande. These lands included the Wallowa Valley, home of
Chief Joseph ''Hin-mah-too-yah-lat-kekt'' (or ''Hinmatóowyalahtq̓it'' in Americanist orthography), popularly known as Chief Joseph, Young Joseph, or Joseph the Younger (March 3, 1840 – September 21, 1904), was a leader of the Wal-lam-wat-kain (Wallowa ...
. The government first opened the Wallowa Valley to settlement in 1867. Surveyors began to come through and would continue until 1869. The Wallowa Valley was partitioned in 1873, with one half for the Nez Perce and the other for settlers. Two years later, in 1875, the government banned the Nez Perce from the valley. The first road into the valley, a
toll road A toll road, also known as a turnpike or tollway, is a public or private road (almost always a controlled-access highway in the present day) for which a fee (or ''Toll (fee), toll'') is assessed for passage. It is a form of road pricing typically ...
, was constructed the same year. The U.S. Government attempted to force the removal of the Nez Perce in 1877; however, this angered the natives, who chose instead to raid the settlers, leading to the
Nez Perce War The Nez Perce War was an armed conflict in 1877 in the Western United States that pitted several bands of the Nez Perce tribe of Native Americans and their allies, a small band of the ''Palouse'' tribe led by Red Echo (''Hahtalekin'') and ...
.
Logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply chain ...
came in the late 1880s, using streams and rivers to transport the wood. A dam was constructed on
Wallowa Lake Wallowa Lake is a ribbon lake south of Joseph, Oregon, United States, at an elevation of . Impounded by high moraines, it was formed by a series of Pleistocene glaciers. On the south end of the lake is Wallowa Lake, Oregon, a small community made ...
in 1884 to help irrigate the valley. In 1908, the first
railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
into the valley was completed. Rail lines were built to the upper valley by the
Union Pacific Railroad The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Paci ...
in 1919, allowing for safer transportation of logs. The dam beneath Wallowa Lake was replaced by a concrete dam in 1916, and a new dam was completed in 1929.


References


External links


Wallowa–Whitman National Forest
U.S. Forest Service
Wallowa Avalanche Center
{{Authority control Landforms of Wallowa County, Oregon Mountain ranges of Oregon Wallowa–Whitman National Forest