Snake River Canyon

Twin Falls, Idaho. Looking downstream (west) from near the southern end of the I.G. Perrine (US Highway 93) bridge. I thought the golf course nestled improbably amongst the craggy outcrops was an interesting touch! As I've noted elsewhere, this canyon was scoured and deepened about 18K years ago by the so-called Bonneville Flood, when Pleistocene Lake Bonneville overtopped a drainage divide into the Snake's drainage basin. The resulting rapid downcutting led to the natural equivalent of a dam failure. Lake Bonneville covered much of western Utah (the Great Salt Lake is a highly shrunken remnant), and it suddenly lost the top few hundred feet of water depth as a result of the flood. Geomorphological evidence indicates that at peak flow this canyon was filled brim to brim.