Bridge of the Gods (geologic event)
Encyclopedia
The Bridge of the Gods was a natural dam created by the Bonneville Slide, a major landslide
that dam
med the Columbia River
near present-day Cascade Locks, Oregon
in the Pacific Northwest
of the United States
. The river eventually breached the bridge and washed much of it away, but the event is remembered in local legends of the Native Americans
as the Bridge of the Gods.
It is now the name of a modern manmade bridge
, the Bridge of the Gods
, across the Columbia River between Oregon
and Washington.
and radiocarbon dating
suggested the landslide occurred between 1060 and 1180 or between 1250 and 1280. The year 1100 A.D. has often been cited as the date of the Bonneville Landslide. More recent work using radiocarbon dating and lichenometry
has suggested dates between 1500 and 1760 or between 1670 and 1760. Some researchers promote a date around 1450 while others favor a date around 1700. If the 1700 date is correct there may be a link to the 1700 Cascadia earthquake.
The Bonneville Landslide sent a large amount of debris south from Table Mountain and Greenleaf Peak
, covering more than 5.5 square miles (14.2 km²). The debris fell into the Columbia Gorge
close to modern-day Cascade Locks, Oregon
, blocking the Columbia River
with a natural dam approximately 200 feet (61 m) high and 3.5 miles (5.6 km) long. The impounded river formed a lake and drowned a forest of trees for about 35 miles (56.3 km). Native Americans may have been able to cross the river on the dam or, as their oral histories say, a bridge. Although no one knows how long it took, the Columbia River eventually broke through the dam and washed away most of the debris, forming the Cascade Rapids. Geologists have determined that debris from several distinct landslides in the same area overlap, forming what is called the Cascades landslide complex. The Bonneville Landslide was the most recent, and perhaps the largest landslide of the complex. Understanding the nature of the landslide complex and mapping the lobes of individual landslide events was done during the 1960s and 1970s. The composite nature of the landslide complex may explain the discrepancies between date estimates of the Bonneville Landslide.
Native American
lore
contains numerous legends to explain the eruptions of Mount St. Helens
and other volcanoes in the Cascade Volcanic Arc
. The most famous of these is the Bridge of the Gods legend told by the Klickitats
. In their tale, the chief of all the gods, Tyhee Saghalie and his two sons, Pahto (also called Klickitat) and Wy'east, traveled down the Columbia River from the Far North in search for a suitable area to settle.
They came upon an area that is now called The Dalles
and thought they had never seen a land so beautiful. The sons quarreled over the land and to solve the dispute their father shot two arrows from his mighty bow; one to the north and the other to the south. Pahto followed the arrow to the north and settled there while Wy'east did the same for the arrow to the south. Saghalie then built Tanmahawis, the Bridge of the Gods, so his family could meet periodically.
When the two sons of the Saghalie fell in love with a beautiful maiden named Loowit, she could not choose between them. The two young chiefs fought over her, burying villages and forests in the process. The area was devastated and the earth shook so violently that the huge bridge fell into the river, creating the Cascades Rapids
of the Columbia River Gorge.
For punishment, Saghalie struck down each of the lovers and transformed them into great mountains where they fell. Wy'east, with his head lifted in pride, became the volcano known today as Mount Hood
and Pahto, with his head bent toward his fallen love, was turned into Mount Adams
. The fair Loowit became Mount St. Helens
, known to the Klickitats as Louwala-Clough which means "smoking or fire mountain" in their language (the Sahaptin
called the mountain Loowit).
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
that dam
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
med the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
near present-day Cascade Locks, Oregon
Cascade Locks, Oregon
Cascade Locks is a city in Hood River County, Oregon, United States. The city took its name from a set of locks built to improve navigation past the Cascades Rapids of the Columbia River. The U.S. federal government approved the plan for the locks in 1875, construction began in 1878, and the locks...
in the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The river eventually breached the bridge and washed much of it away, but the event is remembered in local legends of the Native Americans
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
as the Bridge of the Gods.
It is now the name of a modern manmade bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
, the Bridge of the Gods
Bridge of the Gods (modern structure)
The Bridge of the Gods is a steel truss cantilever bridge that spans the Columbia River between Cascade Locks, Oregon and Washington state near North Bonneville. It is approximately 40 miles east of Portland, Oregon and 4 miles upriver from the Bonneville Dam...
, across the Columbia River between Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and Washington.
Geologic history
The date of the Bonneville Landslide is an unresolved issue among people studying it. Early work based on dendrochronologyDendrochronology
Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year...
and radiocarbon dating
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...
suggested the landslide occurred between 1060 and 1180 or between 1250 and 1280. The year 1100 A.D. has often been cited as the date of the Bonneville Landslide. More recent work using radiocarbon dating and lichenometry
Lichenometry
In archaeology, palaeontology, and geomorphology, lichenometry is a geomorphic method of geochronologic aging that uses lichen growth to determine the age of exposed rock: lichens are presumed to increase in size radially at specific rates as they grow...
has suggested dates between 1500 and 1760 or between 1670 and 1760. Some researchers promote a date around 1450 while others favor a date around 1700. If the 1700 date is correct there may be a link to the 1700 Cascadia earthquake.
The Bonneville Landslide sent a large amount of debris south from Table Mountain and Greenleaf Peak
Greenleaf Peak
Greenleaf Peak is a mountain in the Cascade Range in the U.S. state of Washington, located on the north side of the Columbia River near Table Mountain, in the Columbia River Gorge. The peak lies within the Columbia River Gorge National Scenic Area near Bonneville Dam. It is in elevation...
, covering more than 5.5 square miles (14.2 km²). The debris fell into the Columbia Gorge
Columbia River Gorge
The Columbia River Gorge is a canyon of the Columbia River in the Pacific Northwest of the United States. Up to deep, the canyon stretches for over as the river winds westward through the Cascade Range forming the boundary between the State of Washington to the north and Oregon to the south...
close to modern-day Cascade Locks, Oregon
Cascade Locks, Oregon
Cascade Locks is a city in Hood River County, Oregon, United States. The city took its name from a set of locks built to improve navigation past the Cascades Rapids of the Columbia River. The U.S. federal government approved the plan for the locks in 1875, construction began in 1878, and the locks...
, blocking the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
with a natural dam approximately 200 feet (61 m) high and 3.5 miles (5.6 km) long. The impounded river formed a lake and drowned a forest of trees for about 35 miles (56.3 km). Native Americans may have been able to cross the river on the dam or, as their oral histories say, a bridge. Although no one knows how long it took, the Columbia River eventually broke through the dam and washed away most of the debris, forming the Cascade Rapids. Geologists have determined that debris from several distinct landslides in the same area overlap, forming what is called the Cascades landslide complex. The Bonneville Landslide was the most recent, and perhaps the largest landslide of the complex. Understanding the nature of the landslide complex and mapping the lobes of individual landslide events was done during the 1960s and 1970s. The composite nature of the landslide complex may explain the discrepancies between date estimates of the Bonneville Landslide.
Native American legend
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
lore
Folklore
Folklore consists of legends, music, oral history, proverbs, jokes, popular beliefs, fairy tales and customs that are the traditions of a culture, subculture, or group. It is also the set of practices through which those expressive genres are shared. The study of folklore is sometimes called...
contains numerous legends to explain the eruptions of Mount St. Helens
Mount St. Helens
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is south of Seattle, Washington and northeast of Portland, Oregon. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a...
and other volcanoes in the Cascade Volcanic Arc
Cascade Volcanoes
The Cascade Volcanoes are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 mi ...
. The most famous of these is the Bridge of the Gods legend told by the Klickitats
Klickitat Tribe
The Klickitat are a Native American tribe of the Pacific Northwest. A Shahaptian tribe, their eastern neighbors were the Yakama, who speak a closely related language. Their western neighbors were various Salishan and Chinookan tribes...
. In their tale, the chief of all the gods, Tyhee Saghalie and his two sons, Pahto (also called Klickitat) and Wy'east, traveled down the Columbia River from the Far North in search for a suitable area to settle.
They came upon an area that is now called The Dalles
The Dalles, Oregon
The Dalles is the largest city and county seat of Wasco County, Oregon, United States. The name of the city comes from the French word dalle The Dalles is the largest city and county seat of Wasco County, Oregon, United States. The name of the city comes from the French word dalle The Dalles is...
and thought they had never seen a land so beautiful. The sons quarreled over the land and to solve the dispute their father shot two arrows from his mighty bow; one to the north and the other to the south. Pahto followed the arrow to the north and settled there while Wy'east did the same for the arrow to the south. Saghalie then built Tanmahawis, the Bridge of the Gods, so his family could meet periodically.
When the two sons of the Saghalie fell in love with a beautiful maiden named Loowit, she could not choose between them. The two young chiefs fought over her, burying villages and forests in the process. The area was devastated and the earth shook so violently that the huge bridge fell into the river, creating the Cascades Rapids
Cascades Rapids
The Cascades Rapids were an area of rapids along North America's Columbia River, between the U.S. states of Washington and Oregon. Through a stretch approximately wide, the river dropped about in .-Boat portage:Boat travelers were forced to either portage boats and supplies or pull boats up with...
of the Columbia River Gorge.
For punishment, Saghalie struck down each of the lovers and transformed them into great mountains where they fell. Wy'east, with his head lifted in pride, became the volcano known today as Mount Hood
Mount Hood
Mount Hood, called Wy'east by the Multnomah tribe, is a stratovolcano in the Cascade Volcanic Arc of northern Oregon. It was formed by a subduction zone and rests in the Pacific Northwest region of the United States...
and Pahto, with his head bent toward his fallen love, was turned into Mount Adams
Mount Adams (Washington)
Mount Adams is a potentially activestratovolcano in the Cascade Range and the second-highest mountain in the U.S. state of Washington.Adams is a member of the Cascade Volcanic Arc, and is one of the arc's largest volcanoes,...
. The fair Loowit became Mount St. Helens
Mount St. Helens
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is south of Seattle, Washington and northeast of Portland, Oregon. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a...
, known to the Klickitats as Louwala-Clough which means "smoking or fire mountain" in their language (the Sahaptin
Sahaptin people
The Sahaptin people are a Native American people that inhabited territory along the Columbia River. The Nez Perce tribe is one of the major Sahaptin groups.-Territory:...
called the mountain Loowit).
External links
- Oregonian on possible tie to the Cascadia Earthquake
- Landslide blocks the Columbia River in about 1450
- Use of Dendrochronology to Date and Better Understand the Bonneville Landslide, Columbia River Gorge, Washington
- Another legend of the Bridge of the Gods
- A site on the modern-day Bridge of the Gods, with one excellent image of the slide and some discussion of the history.
- Satellite imagery at Google Maps. The town of Cascade Locks, OregonCascade Locks, OregonCascade Locks is a city in Hood River County, Oregon, United States. The city took its name from a set of locks built to improve navigation past the Cascades Rapids of the Columbia River. The U.S. federal government approved the plan for the locks in 1875, construction began in 1878, and the locks...
, is just upstream (to the right), and the Bonneville DamBonneville DamBonneville Lock and Dam consists of several run-of-the-river dam structures that together complete a span of the Columbia River between the U.S. states of Oregon and Washington at River Mile 146.1. The dam is located east of Portland, Oregon, in the Columbia River Gorge. The primary functions of...
is on the downstream (left) side of the slide. Note how the river dramatically narrows at the location of the slide.