Rhyolite (Pliocene and Miocene).

Rhyolite tuffs and flows of Heise volcanic field (6.6-4.5 Ma; includes Blacktail Creek, Walcott, Conant Creek, and Kilgore tuffs), and rhyolite domes and flows of Magic Reservoir area (6.6-3 Ma). (Quaternary to Eocene Continental Volcanic and Intrusive Rocks).
State Idaho
Name Rhyolite (Pliocene and Miocene).
Geologic age Pliocene and Miocene
Lithologic constituents
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic-tuff, Flow, Dome)

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 Bannock - Bingham - Blaine - Bonneville - Butte - Caribou - Clark - Fremont - Jefferson - Lemhi - Madison - Oneida - Power - Teton