Alluvial-fan deposits.

Gravel and subordinate sand and silt deposited at mouths of canyons; largest fans are in Basin and Range Province in east-central and southeastern Idaho. (Quaternary Sediments).
State Idaho
Name Alluvial-fan deposits.
Geologic age Quaternary
Lithologic constituents
Major
Unconsolidated > Coarse-detrital > Gravel (Alluvial)
Minor
Unconsolidated > Fine-detrital > Silt (Alluvial)
Unconsolidated > Coarse-detrital > Sand (Alluvial)
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 Ada - Adams - Bannock - Bear Lake - Bingham - Blaine - Boise - Bonneville - Butte - Camas - Canyon - Caribou - Cassia - Clark - Custer - Elmore - Franklin - Fremont - Gem - Idaho - Jefferson - Lemhi - Nez Perce - Oneida - Payette - Power - Teton - Twin Falls - Valley - Washington