| Qd - Mine dumps and mill tailings |
| Qc - Colluvial deposits |
| Qf - Alluvial fan deposits |
| Qal - Alluvium of modern channels and flood plains |
| Qef - Earthflow deposits |
| Qrs - Rock slide deposits |
| Qe - Esker deposits |
| Qsd - Undifferentiated surficial deposits |
| Qs - Detrital deposits |
| Qa - Alluvium and glaciofluvial deposits |
| Qao - Alluvium, older, undivided |
| Qls - Landslide deposits |
| Qr - Rock glacier or block field |
| Ql - Lacustrine and glaciolacustrine deposits |
| Qt - Talus, colluvium, and avalanche deposits |
| Qg - Glacial deposits |
| Qh - Hot-spring deposits |
| Qhi - Ice-contact deposits localized by hot springs |
| Qhs - Siliceous hot spring deposits |
| Qhc - Calcareous hot spring deposits |
| Qhe - Hydrothermal-explosion deposits |
| Qm - Morainal deposits |
| Qgt - Glacial till |
| Qtr - Travertine deposits |
| Qgl - Glacial lake deposits |
| Qba - Basalt |
| Qkt - Kame terrace deposits |
| Qo - Outwash deposits |
| Qob - Osprey Basalt |
| Qgc - Basalt of Geode Creek - lava flow |
| Qgcd - Basalt of Geode Creek - dike |
|
| Qgcc - Basalt of Geode Creek - cinder and scoria cone of basalt |
| Qpcp - Plateau Rhyolite - Central Plateau Member - Pitchstone Plateau flow |
| Qpcg - Plateau Rhyolite - Central Plateau Member - Grants Pass flow |
| Qpcy - Plateau Rhyolite - Central Plateau Member - West Yellowstone flow |
| Qpco - Plateau Rhyolite - Central Plateau Member - Tuff of Cold Mountain Creek |
| Qpct - Plateau Rhyolite - Central Plateau Member - Trischman Knob dome |
| Qpck - Plateau Rhyolite - Central Plateau Member - Douglas Knob dome |
| Qpcr - Plateau Rhyolite - Central Plateau Member - Bechler River flow |
| Qpcs - Plateau Rhyolite - Central Plateau Member - Summit Lake flow |
| Qpcb - Plateau Rhyolite - Central Plateau Member - Buffalo Lake flow |
| Qpcc - Plateau Rhyolite - Central Plateau Member - Spring Creek flow |
| Qpci - Plateau Rhyolite - Central Plateau Member - Gibbon River flow |
| Qpcf - Plateau Rhyolite - Central Plateau Member - Solfatara Plateau flow |
| Qpch - Plateau Rhyolite - Central Plateau Member - Hayden Valley flow |
| Qpcn - Plateau Rhyolite - Central Plateau Member - Nez Perce Creek flow |
| Qpcu - Plateau Rhyolite - Central Plateau Member - Spruce Creek flow |
| Qpce - Plateau Rhyolite - Central Plateau Member - Elephant Back flow |
| Qpcw - Plateau Rhyolite - Central Plateau Member - West Thumb flow |
| Qpca - Plateau Rhyolite - Central Plateau Member - Aster Creek flow |
| Qpcl - Plateau Rhyolite - Central Plateau Member - Tuff of Bluff Point |
| Qpcd - Plateau Rhyolite - Central Plateau Member - Dry Creek flow |
| Qpcm - Plateau Rhyolite - Central Plateau Member - Mary Lake flow |
| Qpm - Plateau Rhyolite - Mallard Lake Member - Mallard Lake flow |
| Qpop - Plateau Rhyolite - Mallard Lake Member - Paintpot Hill Dome |
| Qpoc - Plateau Rhyolite - Mallard Lake Member -Geyser Creek dome |
| Qpoh - Plateau Rhyolite - Mallard Lake Member - Gibbon Hill dome |
| Qprc - Plateau Rhyolite - Roaring Mountain Member - Cougar Creek Dome |
| Qprs - Plateau Rhyolite - Roaring Mountain Member - Crystal Spring flow |
| Qpro - Plateau Rhyolite - Roaring Mountain Member - Obsidian Cliff flow |
| Qprr - Plateau Rhyolite - Roaring Mountain Member - Riverside flow |
| Qpow - Plateau Rhyolite - Obsidian Creek Member - Willow Park dome |
| Qpoa - Plateau Rhyolite - Obsidian Creek Member - Apollinaris Spring dome |
| Qpol - Plateau Rhyolite - Obsidian Creek Member - Landmark dome |
| Qpog - Plateau Rhyolite - Obsidian Creek Member - Rhyolite-basalt mixed flows of Gardner River |
| Qpoz - Plateau Rhyolite - Obsidian Creek Member - Rhyolite-basalt mixed flows of Grizzly Lake |
| Qpud - Plateau Rhyolite - Upper Basin Member- Dunraven Road flow |
| Qpuc - Plateau Rhyolite - Upper Basin Member - Canyon flow |
| Qpus - Plateau Rhyolite - Upper Basin Member - Tuff of Sulphur Creek |
| Qpul - Plateau Rhyolite - Upper Basin Member - Scaup Lake flow |
| Qpub - Plateau Rhyolite - Upper Basin Member - Biscuit Basin flow |
| Qpuf - Plateau Rhyolite - Upper Basin Member - Falls River Basalt |
| Qpusl - Plateau Rhyolite - Upper Basin Member - Swan Lake Flat Basalt |
| Qge - Plateau Rhyolite - Upper Basin Member - Gerrit Basalt |
| Qb - Till of Bechler Meadows |
| Qu - Sediments of Upper Falls |
| Qi - Sediments of Inspiration Point |
| Qmr - Madison River Basalt |
| Qfm - Sediments of Flat Mountain Arm |
| Qyl - Lava Creek Tuff |
| Qylb - Lava Creek Tuff - Member B |
| Qyla - Lava Creek Tuff - Member A |
| Qylu - Lava Creek Tuff - Upper part of Member A |
| Qyll - Lava Creek Tuff - Lower part of Member A |
| Quf - Undine Falls Basalt |
| Qjf - Mount Jackson Rhyolite - Flat Mountain flow |
| Qjw - Mount Jackson Rhyolite - Wapiti Lake flow |
| Qjs - Mount Jackson Rhyolite - Stonetop Mountain flow |
| Qjh - Mount Jackson Rhyolite - Mount Haynes flow |
| Qjl - Mount Jackson Rhyolite - Harlequin Lake flow |
| Qmm - Mount Jackson Rhyolite - Moose Creek Butte flow |
| Qmb - Mount Jackson Rhyolite - Big Bear Lake flow |
| Qw - Basalt of Warm River |
| Qn - Sediments and basalts of the Narrows |
| Qiw - Island Park Rhyolite - Warm River Butte dome |
| Qym - Island Park Rhyolite - Mesa Falls Tuff |
| Qhr - Huckleberry Ridge Tuff of Yellowstone Group |
| Qyhc - Huckleberry Ridge Tuff - Member C |
| Qyhb - Huckleberry Ridge Tuff - Member B |
| Qyha - Huckleberry Ridge Tuff - Member A |
| Qbc - Rhyolite of Broad Creek |
| Qj - Junction Butte Basalt |
| Qg2 - Glacial debris of second major glaciation |
| Qg4 - Morainal debris of youngest major glaciation |
| Qsw - Swamp deposits |
|
| Qlg - Landslide and glacial debris |
| Qlc - Lewis Canyon Rhyolite |
| Qel - Pyroxene andesite and basalt of Emerald Lake |
| Qog - Outwash gravel |
| Qsb - Slump blocks |
| Qjlm - Morainal debris of Jackson Lake |
| Qslt - Obsidian sandstone, siltstone and claystone |
| Qbrm - Morainal debris of Buried Ridge |
| QTt - Yellowstone Tuff |
| QTml - Basalt of Mariposa Lake |
| QTh - Heart Lake Conglomerate |
|
| QTi - Igneous Dike |
| QTb - Basalt of uncertain age |
| QTs - Unnamed scoria |
|
| Tcr - Conant Creek Tuff |
| Te - Gravel of Mount Everts |
| Tba - Basalt |
| Tw - Wiggins Formation |
| Twvf - Wiggins Formation - vent facies rocks |
| Twl - Wiggins Formation - lava flows |
| Twi - Wiggins Formation - intrusive rocks |
| Tto - Two Ocean Formation |
| Ttoa - Two Ocean Formation - ash bed |
| Tv - Volcaniclastic rocks of uncertain correlation |
| Tdaf - Dacite flows |
| Tda - Dacite intrusive rocks |
| Trl - Rhyodacite porphyry of Lulu Pass |
| Trh - Rhyodacite porphyry of Henderson Mountain |
| Tlpl - Latite and porphyritic latite |
| Tab - Andesite breccia |
| Tsh - Shoshonite |
| Tlrp - Rhyodacite porphyry |
| Tltp - Latite porphyry |
| Tat - Augite trachyandesite |
| Tdn - Diorite and norite |
| Th - Hominy Peak Formation |
| Ttli - Intrusive rocks of Two Ocean and Langford Formations |
| Tl - Langford Formation |
|
| Tli - Langford Formation - intrusive rocks |
| Tlv - Langford Formation - vent facies |
|
| Tla - Langford Formation - alluvial facies |
| Tlp - Langford Formation - Promontory Member |
| Tlf - Langford Formation - andesitic lava flows |
| Tt - Trout Peak Trachyandesite - main body |
| Ttp - Trout Peak Trachyandesite - Pacific Creek Tuff Member |
| Tta - Trout Peak Trachyandesite - andesitic volcanic sediments |
| Tfm - Complex of Fisher Mountain area |
| Tbam - Breccia of Alice E. Mine area |
| Tbh - Breccia of Homestake Mine area |
| Tww - Wapiti Formation |
| Twa - Wapiti Formation - alluvial facies |
| Twv - Wapiti Formation - vent facies |
| Twf - Wapiti Formation - mafic lava flows |
|
| Tch - Crescent Hill Basalt |
| Tm - Mount Wallace Formation - main body |
| Tms - Mount Wallace Formation - Slough Creek Tuff Member |
| Tb - Olivine basalt laccolith |
| Ti - Quartz monzonite porphyry |
| Tlr - Lamar River Formation |
| Tlri - Lamar River Formation - bodies of intrusive breccia and dikes associated with the Sulphur Creek Stock |
| Tlrd - Lamar River Formation - Sulphur Creek Stock |
| Tlra - Lamar River Formation - alluvial facies |
| Tlia - Lamar River Formation - autobrecciated intrusive andesite |
| Tec - Lamar River Formation - Elk Creek Basalt Member |
|
| Tlrv - Lamar River Formation - vent facies |
| Tlrf - Lamar River Formation - andesite flows |
|
| Tlrc - Lamar River and Cathedral Cliffs Formations, undivided |
| Tai - Intrusive rocks of Absaroka Volcanics Supergroup |
| Ts - Sepulcher Formation |
| Tsf - Sepulcher Formation - Fortress Mountain Member |
| Tsd - Sepulcher Formation - Daly Creek Member |
| Tlc - Sepulcher Formation - Lost Creek Member |
| Tsc - Sepulcher Formation - Nonvolcanic conglomerate, fanglomerate, and breccia facies |
| Tsec - Sepulcher Formation - Elk Creek Basalt Member |
| Tic - Intrusive Andesite, Cathedral Cliffs Formation, and Lamar River Formation |
|
| Tcc - Cathedral Cliff Formation |
| Tc - Crandall Conglomerate |
| Tmz - Monzodiorite of Independence area |
| Tfpy - Felsic pyroclastic rocks |
| Trs - Rhyolite or rhyolitic sediment |
| Tir - Intrusive rocks, undivided |
| Tav - Absaroka Volcanics Supergroup |
| Tae - Andesite, epiclastic, of Hyalite Peak Volcanics |
| Tanf - Andesite flows of Hyalite Peak Volcanics |
| Tavv - Vent facies of Hyalite Peak Volcanics |
| Tigr - Rhyodacite, quartz latite, quartz monzonite, and granodiorite in the Gallatin Range |
| Tap - Porphyritic andesite and andesite porphyry |
| Trpq - Quartz "eye" rhyodacite porphyry |
| Tds - Diorite of Scotch Bonnet Mountain |
| Ttap - Trachyandesite porphyry |
| Tr - Rhyolite porphyry lava flows |
| Tri - Rhyolite porphyry dike |
| Tdp - Dacite porphyry |
| Twr - White River Formation |
| Tbc - Tuff of Boone Creek |
|
| Tbr - Unnamed basalt breccia |
| Tcl - Colter Formation |
| Tsr - Sediment or sedimentary rocks, undivided |
| TKp - Pinyon Conglomerate |
| TKv - Volcanic rocks |
| TPCi - Intermediate and mafic intrusive rocks |
| Kql - Quartz latite porphyry |
| Ksg - Syenite of Goose Lake |
|
| Krp - Rhyodacite porphyry |
|
| Kh - Harebell Formation |
| Kb - Bacon Ridge Sandstone |
| Kl - Landslide Creek Formation, Everts Formation, Eagle Sandstone, Telegraph Creek Formation, Cody Shale, Frontier Formation |
| Kc - Cody Shale |
| Kf - Frontier Formation |
| Ksu - Upper Cretaceous sedimentary rocks, undivided |
| Ksul - Upper and Lower Cretaceous sedimentary rocks, undivided |
| Kk - Kootenai Formation |
| Kmk - Mowry Shale, Thermopolis Shale, and Kootenai Formation |
| Kmt - Mowry and Thermopolis Shales |
| Kt - Thermopolis Shale |
| Ktu - Thermopolis Shale - upper part |
| Kts - Themopolis Shale - Sandstone Member |
| Kmd - Thermopolis Shale - Muddy Sandstone Member |
| Kcvr - Thermopolis Shale - Rusty Beds Member |
| KJmv - Thermopolis Shale - variegated sequence underlying Rusty Beds Member |
| Kmr - Mowry Shale |
| Ks - Sedimentary rocks, undivided |
|
| Kss - Lenticular sandstone/shale sequence |
| Ksb - Unnamed lenticular sandstone/shale/bedrock sequence |
| Kdi - Diorite |
| KJcm - Clovely and Morrison Formations |
| Jm - Morrison Formation |
| Jsg - Sundance and Gypsum Spring Formations |
| Jus - Upper Sundance Formation |
| Jls - Lower Sundance Formation |
| Jgs - Gypsum Spring Formation |
| Je - Ellis Group - Swift, Rierdon, and Sawtooth Formations, undivided |
| JTRs - Sedimentary rocks, undivided |
| TRcd - Chugwater and Dinwoody Formations, undivided |
| TRc - Chugwater Formation |
| TRp - Chugwater Formation - Popo Agie Member |
| TRrp - Chugwater Formation - Red Peak Member |
| TRa - Chugwater Formation - Alcova Limestone Member |
| TRd - Dinwoody Formation |
| TRtw - Thaynes, Woodside, and Dinwoody Formations |
| Pp - Phosphoria Formation |
| Ps - Shedhorn Sandstone |
| PMs - Sedimentary rocks, undivided |
| PNq - Quadrant Sandstone |
| PNMta - Tensleep Sandstone and Amsden Formation |
| PNMa - Amsden Formation |
| Mm - Madison Group |
| Ml - Lodgepole Limestone |
| MCu - Upper Mississippian to Middle Cambrian rocks, undivided |
| Dtj - Three Forks and Jefferson Formations, undivided |
| Dt - Three Forks Formation |
| Dj - Jefferson Formation |
| Dd - Darby Formation |
| DOs - Sedimentary rocks, undivided |
| DOt - Three Forks Formation, Jefferson Formation, and Bighorn Dolomite |
| Ob - Bighorn Dolomite |
| OCbp - Bighorn Dolomite, Snowy Range Formation, and Pilgrim Limestone, undivided |
| OCbg - Bighorn Dolomite and Gallatin Limestone, undivided |
| Csrp - Snowy Range and Pilgrim Formations |
| Csr - Snowy Range Formation |
| Cpi - Pilgrim Limestone |
| Cu - Upper and Middle Cambrian rocks, undivided |
|
| Cgp - Gallatin Limestone and Park Shale |
| Cgv - Gros Ventre Formation |
| Cdc - Death Canyon Limestone |
| Cpf - Park, Meagher, Wolsey, and Flathead Formations |
| Cpa - Park Shale |
| Cm - Meagher Limestone |
| Cwf - Wolsey Shale and Flathead Sandstone |
| Cw - Wolsey Shale |
| Cf - Flathead Sandstone |
| Cs - Sedimentary rocks, undivided |
| PZs - Sedimentary rocks, undivided |
| PCWqd - Quartz dolerite |
| PCWmd - Metadolerite |
| PCWom - Olivine metagabbro |
| PCWmp - Metadolerite porphyry |
|
| PCWg - Granitic rocks |
| PCWu - Ultramafic rocks |
| PCWgn - Layered gneiss |
| PCmi - Mafic intrusive rocks |
| PCamh - Amphibolite and hornblende gneiss, Stillwater Complex |
| PCgn - Gneissic rocks |
| PCsh - Schist and hornfels |
| PCmy - Mylonite |
| PCq - Quartzite |
| PCt - Tremolite marble |
| PCm - Mica schist |
| PCa - Amphibolite |
| PCd - Dolomite |
| PCn - Noritic gabbro |
| PCs - Schist and gneiss |
| PCmg - Metamorphic rocks, undivided |
| PCg - Granite gneiss |
| cd - Carbonate dike |
| qz-v - Quartz vein |
|
| water |
