Dry Falls
Encyclopedia
Dry Falls is a 3.5 mile long scalloped precipice in central Washington, on the opposite side of the Upper Grand Coulee
from the Columbia River
, and at the head of the Lower Grand Coulee. Ten times the size of Niagara
, Dry Falls is thought to be the greatest known waterfall that ever existed. According to the current geological model, catastrophic flooding
channeled water at 65 miles per hour through the Upper Grand Coulee and over this 400 feet (121.9 m) rock face at the end of the last ice age. At this time, it is estimated that the flow of the falls was ten times the current flow of all the rivers in the world combined.
Nearly twenty thousand years ago, as glaciers moved south, an ice sheet dammed the Clark Fork (river)
near Sandpoint, Idaho. Consequently, a significant portion of western Montana flooded, forming the gigantic Lake Missoula. About the same time, Glacial Lake Columbia
was formed on the ice-dammed Columbia River behind the Okanogan lobe of the Cordilleran Ice Sheet. Lake Columbia's overflow – the diverted Columbia River – drained first through Moses Coulee and as the ice dam
grew, later through the Grand Coulee.
Eventually, water in lake Missoula rose high enough to float the ice dam
until it gave way, and a portion of this cataclysmic flood spilled into Glacial Lake Columbia, and then down the Grand Coulee. It is generally accepted that this process of ice-damming of the Clark Fork, refilling of Lake Missoula and subsequent cataclysmic flooding happened dozens of times over the years of the last Ice Age.
This sudden flood put parts of Idaho
, Washington, and Oregon
under hundreds of feet of water in just a few days. These extraordinary floods greatly enlarged the Grand Coulee
and Dry Falls in a short period. The large plunge pools at the base of Dry Falls were created by these floods.
Once the ice sheet that obstructed the Columbia melted, the river returned to its normal course, leaving the Grand Coulee and the falls dry. Today, this massive cliff can be viewed from the Dry Falls Interpretive Center, part of Sun Lakes State Park
, and located on Route 17 near the town of Coulee City
. Admission is free.
Grand Coulee
The Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about sixty miles southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee....
from 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...
, and at the head of the Lower Grand Coulee. Ten times the size of Niagara
Niagara Falls
The Niagara Falls, located on the Niagara River draining Lake Erie into Lake Ontario, is the collective name for the Horseshoe Falls and the adjacent American Falls along with the comparatively small Bridal Veil Falls, which combined form the highest flow rate of any waterfalls in the world and has...
, Dry Falls is thought to be the greatest known waterfall that ever existed. According to the current geological model, catastrophic flooding
Missoula Floods
The Missoula Floods refer to the cataclysmic floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. The glacial flood events have been researched since the 1920s...
channeled water at 65 miles per hour through the Upper Grand Coulee and over this 400 feet (121.9 m) rock face at the end of the last ice age. At this time, it is estimated that the flow of the falls was ten times the current flow of all the rivers in the world combined.
Nearly twenty thousand years ago, as glaciers moved south, an ice sheet dammed the Clark Fork (river)
Clark Fork (river)
The Clark Fork is a river in the U.S. states of Montana and Idaho, approximately long. The largest river by volume in Montana, it drains an extensive region of the Rocky Mountains in western Montana and northern Idaho in the watershed of the Columbia River, flowing northwest through a long...
near Sandpoint, Idaho. Consequently, a significant portion of western Montana flooded, forming the gigantic Lake Missoula. About the same time, Glacial Lake Columbia
Glacial Lake Columbia
Glacial Lake Columbia was the lake formed on the ice-dammed Columbia River behind the Okanogan lobe of the Cordilleran Ice Sheet when the lobe covered of the Waterville Plateau west of Grand Coulee in central Washington state during the Wisconsin glaciation. Lake Columbia was a substantially...
was formed on the ice-dammed Columbia River behind the Okanogan lobe of the Cordilleran Ice Sheet. Lake Columbia's overflow – the diverted Columbia River – drained first through Moses Coulee and as the ice dam
Ice dam
An ice dam occurs when water builds up behind a blockage of ice. Ice dams can occur in various ways.-Caused by a glacier:Sometimes a glacier flows down a valley to a confluence where the other branch carries an unfrozen river...
grew, later through the Grand Coulee.
Eventually, water in lake Missoula rose high enough to float the ice dam
Ice dam
An ice dam occurs when water builds up behind a blockage of ice. Ice dams can occur in various ways.-Caused by a glacier:Sometimes a glacier flows down a valley to a confluence where the other branch carries an unfrozen river...
until it gave way, and a portion of this cataclysmic flood spilled into Glacial Lake Columbia, and then down the Grand Coulee. It is generally accepted that this process of ice-damming of the Clark Fork, refilling of Lake Missoula and subsequent cataclysmic flooding happened dozens of times over the years of the last Ice Age.
This sudden flood put parts of Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Washington, and 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...
under hundreds of feet of water in just a few days. These extraordinary floods greatly enlarged the Grand Coulee
Grand Coulee
The Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about sixty miles southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee....
and Dry Falls in a short period. The large plunge pools at the base of Dry Falls were created by these floods.
Once the ice sheet that obstructed the Columbia melted, the river returned to its normal course, leaving the Grand Coulee and the falls dry. Today, this massive cliff can be viewed from the Dry Falls Interpretive Center, part of Sun Lakes State Park
Sun Lakes State Park
Sun Lakes State Park is a camping park with of freshwater shoreline at the foot of Dry Falls, which is located near Coulee City, Washington. Formed by the Missoula Floods, Dry Falls is the site of a former waterfall which is now a stark cliff, high and wide. When the floods occurred, the...
, and located on Route 17 near the town of Coulee City
Coulee City, Washington
Coulee City is a town in Grant County, Washington, United States. The population was 600 at the 2000 census.-Geography:Coulee City is located at ....
. Admission is free.