Missoula Flood deposits.

Gravel, sand, and silt near Coeur d'Alene and Sandpoint that were carried by outburst floods from Glacial Lake Missoula (20-15 ka). Floods also flowed back up the Snake and Clearwater rivers to Kamiah. Missoula Flood slack-water deposits cover Lake Bonneville deposits in the Lewiston area. (Quaternary Sediments).
State Idaho
Name Missoula Flood deposits.
Geologic age Pleistocene
Lithologic constituents
Major
Unconsolidated > Coarse-detrital > Gravel (Fluvial, Lacustrine)
Unconsolidated > Fine-detrital > Silt (Fluvial, Lacustrine)
Unconsolidated > Coarse-detrital > Sand (Fluvial, Lacustrine)
References

Lewis, Reed S., Link, Paul K., Stanford, Loudon R., and Long, Sean P., Geologic Map of Idaho, 2012, Idaho Geological Survey, Geologic Map 9 (M-9); Scale 1:500,000.

NGMDB product
Counties Bonner - Idaho - Kootenai - Lewis