AlanLichty
Moderator
The base of the Bridge of the Gods landslide has some interesting history. On the far side of the river on the right in the scene below you can still see the height of the slide debris a couple hundred feet above the current river and roadways. The Columbia River eventually breached the earthen dam and formed the U shaped gap still visible today with the town of Cascade Locks sitting near the bottom of the U. When most of the loose debris had washed away what was left was an underwater field of large boulders that formed the Cascade Rapids. The rapids were great for the native tribes who were fishing for the salmon but not so much for the Euro-American settlers determined to get to the Willamette River valley beyond. More than a few boats were unable to navigate the rapids. The Columbia River dropped 40' in less than 2 miles through the underwater boulder field.
Starting in the late 1870's the settlers started building a set of river locks to get around the rapids. They dug a channel into the base of the rapids and extended it up to the water just upstream from the rapids. The locks enabled stern wheelers to safely navigate the river from 1896 up until the rapids were entirely submerged in the early 1930's by water backing up from the construction of Bonneville Dam a few miles downstream. The locks isolated a chunk of land now known as Thunder Island just to the left of the modern community of Cascade Locks. Only the top portions of the locks are still visible now with the Columbia approximately 60' deep as you see it near the modern Bridge of the Gods. Bonneville Dam submerged the rapids and eliminated further need for these locks with the dam having a set of locks to enable river traffic.
C&C always welcome.
Starting in the late 1870's the settlers started building a set of river locks to get around the rapids. They dug a channel into the base of the rapids and extended it up to the water just upstream from the rapids. The locks enabled stern wheelers to safely navigate the river from 1896 up until the rapids were entirely submerged in the early 1930's by water backing up from the construction of Bonneville Dam a few miles downstream. The locks isolated a chunk of land now known as Thunder Island just to the left of the modern community of Cascade Locks. Only the top portions of the locks are still visible now with the Columbia approximately 60' deep as you see it near the modern Bridge of the Gods. Bonneville Dam submerged the rapids and eliminated further need for these locks with the dam having a set of locks to enable river traffic.
C&C always welcome.
