The Missoula floods were cataclysmic glacial lake outburst floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon. After the lake drained, the ice would reform, creating Glacial Lake Missoula again.
Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about 60 miles (100 km) southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee.
A glacial erratic is a glacially deposited rock differing from the type of rock native to the area in which it rests. Erratics, which take their name from the Latin word errare, are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock in Alberta.
The Channeled Scablands are a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods within the southeastern part of Washington state. The Channeled Scablands were scoured by more than 40 cataclysmic floods during the Last Glacial Maximum and innumerable older cataclysmic floods over the last two million years. These floods were periodically unleashed whenever a large glacial lake broke through its ice dam and swept across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch. The last of the cataclysmic floods occurred between 18,200 and 14,000 years ago.
J Harlen Bretz was an American geologist, best known for his research that led to the acceptance of the Missoula Floods and for his work on caves.
Hickory Run State Park is a 15,990-acre (6,471 ha) Pennsylvania state park in Kidder and Penn Forest Townships in Carbon County, Pennsylvania in the United States. The park is spread across the Pocono Mountains. The park is easily accessible from Interstate 476 and Interstate 80.
Joseph Thomas Pardee was a U.S. geologist who worked for the U.S. Geological Survey, and contributed to the understanding of the origin of the Channeled Scablands. He discovered the trail of evidence left by Glacial Lake Missoula, a lake created by an ice dam 23 miles (37 km) wide and 0.5 miles (0.8 km) high during the most recent ice age. He discovered that when the dam broke, the water flowed towards the scablands, supporting J Harlen Bretz's theory of the cataclysmic floods.
Drumheller Channels National Natural Landmark showcases the Drumheller Channels, which are the most significant example in the Columbia Plateau of basalt butte-and-basin Channeled Scablands. This National Natural Landmark is an extensively eroded landscape, located in south central Washington state characterized by hundreds of isolated, steep-sided hills (buttes) surrounded by a braided network of numerous channels, all but one of which are currently dry. It is a classic example of the tremendous erosive powers of extremely large floods such as those that reformed the Columbia Plateau volcanic terrain during the late Pleistocene glacial Missoula Floods.
Boulder Park National Natural Landmark, of Douglas County, Washington, along with the nearby McNeil Canyon Haystack Rocks and Sims Corner Eskers and Kames natural landmarks, illustrate well-preserved examples of classic Pleistocene ice stagnation landforms that are found in Washington. These landforms include numerous glacial erratics and haystack rocks that occur near and on the Withrow Moraine, which is the terminal moraine of the Okanogan ice lobe.
The Blue Hills just west of Bremerton, Washington, also called the Bremerton Hills, Bald Hills, and Wildcat Hills, consist of Gold Mountain, Green Mountain, and several informally named hills. Reaching an elevation of 1761 feet, a thousand feet above the glacial till that fills the Puget Lowland, they form a prominent landmark visible around the region. They are formed of uplifted blocks of marine basalts, the steep-walled canyons between the various summits being the fissures between the blocks. In addition to Gold Mountain and Green Mountain are several other prominent peaks unofficially named according to their elevation :
Glacial erratic boulders of King County are large glacial erratic boulders of rock which were moved into King County, Washington by glacial action during previous ice ages.
Glacial erratic boulders of Snohomish County are large glacial erratic boulders of rock which were moved to Snohomish County, Washington by glacial action during previous ice ages.
The Lawrence Lake erratic is a glacial erratic boulder near Lake Lawrence in Thurston County, Washington. The boulder is about 15 feet (4.6 m) tall. Lake Lawrence itself was formed when the Vashon Glaciation created most of the topography seen in the Puget Sound region. The erratic is one of the southernmost in the Puget Sound region, near the limit of the Yelm lobe of the Vashon Glacier in the Rainier area.
Many glacial erratic boulders can be found in the Puget Sound region as far south as the Yelm area where the Puget Lobe of the glacier reached its maximum extent.
Glacial erratic boulders in Island County are a remnant of the Pleistocene glaciation that created Puget Sound and transformed the surfaces of what are now Island County's main landmasses: Whidbey Island and Camano Island. South of Deception Pass, the two islands' surfaces and beaches are completely composed of glacial till. Abundant glacial erratic boulders lie on the islands, their beaches, and under the near-shore waters.
Hills in the Puget Lowland, between the Cascades and the Olympic Mountains, including the entire Seattle metropolitan area, are generally between 350–450 feet (110–140 m) and rarely more than 500 feet (150 m) above sea level. Hills are often notable geologically and for social reasons, such as the seven hills of Seattle.
During the Vashon Glaciation a series of lakes formed along the southern margin of the Cordilleran Ice Cap. In the Puget Sound depression, a series of lakes developed, of which Lake Russell was the largest and the longest lasting. Early Lake Russell’s surface was at 160 ft (49 m) above sea level, draining across the divide at Shelton, Washington into early Glacial Lake Russell. When the ice margin receded northward, the lake expanded. When it reached the Clifton channel outlet, the water levels dropped to 120 ft (37 m) above sea level. The new longer and lower level lake is referred to as Lake Hood. The glacier continued to retreat until the northern outlet of the Hood Canal was reached as the water level equalized with Glacial Lake Russell becoming part of that body of water.
During the Vashon Glaciation a series of lakes formed along the southern margin of the Cordilleran Ice Cap. In the Hood Canal depression, two significant lake stages existed, Lake Skokomish and Lake Hood. Early Lake Skokomish’s surface was at 350 ft (110 m) above sea level, draining across the divide at Shelton, Washington into early Glacial Lake Russell. As the glacier receded northward, this freshwater lake grew in size, until the ice was north of the Clifton channel. With the opening of the Clifton channel, the water dropped to 160 m (520 ft) above sea level. This longer and lower level lake is referred to as Lake Hood. The glacier continued to recede northward until it reached the Poulsbo channel. Here, the water level equalized to Glacial Lake Russell no longer having a separate identify.
Lake Tacoma is the name given the freshwater lake in the basin of the Puyallup River and the Green River at the point in time that the Vashon Glacier had receded northward into Commencement Bay. Prior to this, it was referred to as the Lake Puyallup. The bluff on which this city is built is used as the landmark where Lake Puyallup ceased and it became Lake Tacoma.
