On the bridge going into Twin Falls, ID: Snake River Canyon is a canyon formed by the Snake River in the Magic Valley region of southern Idaho, forming part of the boundary between Twin Falls County to the south and Jerome County to the north. The canyon ranges up to 500 feet deep and 0.25 miles wide, and runs for just over 50 miles. In the past it was generally believed the Snake River Canyon was created by a cataclysmic flood caused by water released from Lake Bonneville approximately 15,000 years ago. However, as of 2000, geologists believe that while the canyon was shaped by the flood, its basic structure predated it.

52,000 years ago, the lava from McKinney Butte dams formed Snake River near Bliss. 17,400 years ago, the catastrophic Bonneville Flood eroded narrow sections of the Snake River Canyon and deposited massive boulders in wide sections.

https://www.volcanocafe.org/the-snake-river/