Bonneville flood

Ancient Red Rock Pass was the site of two alluvial fans descending from opposite sides of the notch, forming a natural dam.

It also carved and increased in size many other tributary canyons, including those of the Bruneau River and Salmon Falls Creek.

This surge carried up into the Cache Valley and resulted in the failure of the natural dam at the Zenda threshold just north of Red Rock Pass.

[10] Although the peak of the flood lasted a few weeks at most, erosion at Red Rock Pass continued for a few years before water ceased to spill over.

The flood transformed the Snake River Plain into a series of channeled scablands resembling the Columbia Plateau.