The Submerged Forest, by Sarah Hall // bc006476; OrHi 89660
About 25 miles above the Cascade Rapids on the Columbia River, a large number of tree stumps break the surface of the water in what has been dubbed the “submerged forest.” Most of this area has been inundated behind Bonneville Dam, but many of the trees are still visible.
These petrified stumps, the result of centuries of geological activity, have caught the eye of many northwest explorers and travelers. Lewis and Clark were the first Euro Americans to record this phenomenon. In an April 14, 1806 entry, Lewis observed “the trunks of many large pine trees standing erect as they grew at present in 30 feet water; they are much doated and none of them vegetating.”
Subsequent travelers, explorers, and scientists, including the Wilkes Expedition in 1841, also tried to make sense of the odd formation. Modern scientists theorize that the trees may have been submerged as the result of a strong regional earthquake in about 1700, possibly the same earthquake that caused a tsunami that ravaged the Northwest coast that same year.
The earthquake caused a landslide that created a large earthen dam in the river. This dam stopped the river’s flow and submerged the still-living trees under water and tons of accumulated silt. Eventually, the dam broke, the waters receded, and the silt gradually eroded, exposing the dead, yet preserved, tree stumps and trunks.
The submerged forest has become an Oregon landmark, famously photographed by Sarah Hall Ladd in 1902 and made part of the penny postcard series in the 1920s.