Listed below are the currently available Geologic Aquifer Codes in GWIC.
| Code | Description |
|---|---|
| 100UDFD | CENOZOIC UNDIFFERENTIATED |
| 110ADKB | ANDERSON-DIETZ1 CLINKER |
| 110ALVF | ALLUVIAL FAN DEPOSITS (QUATERNARY) |
| 110ALVM | ALLUVIUM (QUATERNARY) |
| 110ANKB | ANDERSON CLINKER |
| 110CDKB | C&D CLINKER |
| 110CKKB | COOK CLINKER |
| 110CLNK | QUATERNARY CLINKER DEPOSITS |
| 110CLVM | COLLUVIUM (QUATERNARY) |
| 110CNKB | CANYON CLINKER |
| 110DIKB | DIETZ CLINKER |
| 110FRKB | FERRY CLINKER |
| 110LCSR | LACUSTRINE DEPOSITS (QUATERNARY) |
| 110LDSL | QUATERNARY LANDSLIDE DEPOSITS |
| 110ODKB | ODELL CLINKER |
| 110PDMN | PEDIMENT DEPOSITS (QUATERNARY) |
| 110PWKB | PAWNEE CLINKER |
| 110SNGR | SAND AND GRAVEL (QUATERNARY) |
| 110SWKB | SAWYER CLINKER |
| 110TRRC | TERRACE DEPOSITS (QUATERNARY) |
| 110UDFD | QUATERNARY UNDIFFERENTIATED |
| 110VLCC | VOLCANICS (QUATERNARY) |
| 110WAKB | WALL CLINKER |
| 110YRT1 | YELLOWSTONE RIVER TERRACE-1 |
| 111ALVF | ALLUVIAL FAN DEPOSITS (HOLOCENE) |
| 111ALVM | ALLUVIUM (HOLOCENE) |
| 111CLVM | COLLUVIUM (HOLOCENE) |
| 111DDGP | DREDGE PILINGS (PLACER TAILINGS) |
| 111DMCT | HOLOCENE SILT AND CLAY |
| 111FILL | HOLOCENE MAN-DEPOSITED FILL MATERIALS |
| 111LCSR | LACUSTRINE DEPOSITS (HOLOCENE) |
| 111MDMP | MINE DUMPS |
| 111MTLG | MINE TAILINGS |
| 111PDMN | PEDIMENT DEPOSITS (HOLOCENE) |
| 111SICL | HOLOCENE SILT AND CLAY |
| 111SNGR | SAND AND GRAVEL (HOLOCENE) |
| 111SPBK | COAL MINE SPOIL BANKS |
| 111TGPD | TAILING PONDS |
| 111TRRC | TERRACE DEPOSITS (HOLOCENE) |
| 111UDFD | HOLOCENE UNDIFFERENTIATED |
| 111VLCC | VOLCANICS (HOLOCENE) |
| 111WAST | METAL MINE WASTE ROCK |
| 111WDBL | WIND BLOWN DEPOSITS (HOLOCENE) |
| 112ALMN | ALTAMONT MORAINE |
| 112ALVF | ALLUVIAL FAN DEPOSITS - PLEISTOCENE |
| 112ALVM | ALLUVIUM (PLEISTOCENE) |
| 112CNCK | CRANE CREEK GRAVEL |
| 112CRRC | CARTWRIGHT GRAVEL (PLEISTOCENE) |
| 112DMCT | PLEISTOCENE DIAMICT: DEBRIS FLOW GLACIAL OR OTHER |
| 112DRFT | GLACIAL DRIFT |
| 112GFLK | GLACIAL GREAT FALLS LAKE SEDIMENTS |
| 112GLCC | GLACIOLACUSTRINE DEPOSITS (PLEISTOCENE) |
| 112LCSR | LACUSTRINE DEPOSITS (PLEISTOCENE) |
| 112LKML | GLACIAL LAKE MISSOULA BEDS |
| 112LONE | LONEPINE AQUIFER (LITTLE BITTERROOT VALLEY) |
| 112OTSH | GLACIAL OUTWASH (PLEISTOCENE) |
| 112RKGL | ROCK GLACIER (UPPER PLEISTOCENE) |
| 112SDMS | SEDIMENTS (PLEISTOCENE) |
| 112SICL | PLEISTOCENE SILT AND CLAY |
| 112SNGR | SAND AND GRAVEL (PLEISTOCENE) |
| 112TILL | GLACIAL TILL |
| 112TRRC | TERRACE DEPOSITS (PLEISTOCENE) |
| 112UDFD | PLEISTOCENE UNDIFFERENTIATED |
| 112VFAL | PLEISTOCENE VALLEY-FILL ALLUVIUM CLEAN SAND&GRAV |
| 112VLCC | VOLCANICS (PLEISTOCENE) |
| 112WDBL | WIND-BLOWN DEPOSITS (PLEISTOCENE) |
| 112WIOT | WIOTA GRAVELS (PLEISTOCENE) |
| 112YRT2 | YELLOWSTONE RIVER TERRACE-2 |
| 112YRT3 | YELLOWSTONE RIVER TERRACE-3 |
| 112YRT4 | YELLOWSTONE RIVER TERRACE-4 |
| 120BLMN | BELMONT PORPHRY |
| 120BRKR | BARKER PORPHYRY |
| 120BZMN | BOZEMAN GROUP |
| 120CPCK | CARPENTER CREEK GRANITE PORPHYRY |
| 120DMCT | TERTIARY DIAMICT: DEBRIS FLOW GLACIAL OR OTHER |
| 120DMLM | DRUMLUMMON PORPHYRY |
| 120FWLS | FRESH WATER LIMESTONE OF PLIOCENE AND MIOCENE AGE WITHIN TUFFACEOUS DEPOSITS |
| 120LCSR | LACUSTRINE DEPOSITS (TERTIARY) |
| 120LNLY | LINLEY CONGLOMERATE |
| 120PLNC | PLUTONIC ROCKS (TERTIARY - CRETACEOUS) |
| 120PNTO | PINTO DIORITE |
| 120SCRK | SNOW CREEK QUARTZ PORPHYRY |
| 120SDMS | SEDIMENTS (TERTIARY) |
| 120SFRD | STANFORD CONGLOMERATE |
| 120SICL | TERTIARY SILT AND CLAY |
| 120SNGR | SAND AND GRAVEL (TERTIARY) |
| 120TRRC | TERRACE DEPOSITS (TERTIARY) |
| 120UDFD | TERTIARY UNDIFFERENTIATED |
| 120VLCC | VOLCANICS (TERTIARY) |
| 120WOLF | WOLF PORPHYRY |
| 121BLCK | BLACK TAIL DEER CREEK FORMATION |
| 121CSTL | CASTLE GRANITE (PLIOCENE) |
| 121FLXV | FLAXVILLE GRAVELS (PLIOCENE-MIOCENE) |
| 121FREL | FORT ELLIS BEDS (PLIOCENE) |
| 121LCSR | LACUSTRINE DEPOSITS (PLIOCENE) |
| 121PLNC | PLUTONIC ROCKS (PLIOCENE) |
| 121SDMS | SEDIMENTS (PLIOCENE) |
| 121SXCK | SIXMILE CREEK FORMATION (PLIOCENE) |
| 121UDFD | PLIOCENE UNDIFFERENTIATED |
| 121VLCC | VOLCANIC ROCKS (PLIOCENE) |
| 122ARKR | ARIKAREE FORMATION (MIOCENE) |
| 122CHLS | CHALLIS VOLCANICS (MIOCENE-OLIGOCENE-EOCENE) |
| 122CLLS | CHALLIS VOLCANICS-EOCENE |
| 122DPRV | DEEP RIVER BEDS (MIDDLE MIOCENE) |
| 122FRLG | FORT LOGAN BEDS (LOWER MIOCENE) |
| 122LCSR | LACUSTRINE DEPOSITS (MIOCENE) |
| 122MDSV | MADISON VALLEY FORMATION |
| 122PLNC | PLUTONIC ROCKS (MIOCENE) |
| 122RMRD | RIMROAD GRAVEL OR FORMATION |
| 122SDMS | SEDIMENTS (MIOCENE) |
| 122UDFD | MIOCENE UNDIFFERENTIATED |
| 122VLCC | VOLCANIC ROCKS (MIOCENE) |
| 122WDMN | WOOD MOUNTAIN GRAVELS (SASKATCHEWAN) |
| 123ABRD | ANCESTRAL BITTERROOT RIVER DEPOSITS |
| 123CBGA | CLIMBING ARROW FORMATION (OF BOZEMAN GROUP) |
| 123CHLS | CHALLIS VOLCANICS (OLIGOCENE) |
| 123CKRC | COOK RANCH FORMATION |
| 123CPHL | CYPRESS HILLS FORMATION (SASKATCHEWAN) |
| 123DBCK | DUNBAR CREEK FORMATION (OF BOZEMAN GROUP) |
| 123LCSR | LACUSTRINE DEPOSITS (OLIGOCENE) |
| 123PLNC | PLUTONIC ROCKS (OLIGOCENE) |
| 123PPSP | PIPESTONE SPRINGS FORMATION |
| 123RDBF | RED BLUFF FORMATION (LATE EOCENE-OLIGOCENE) |
| 123SDMS | SEDIMENTS (OLIGOCENE) |
| 123UDFD | OLIGOCENE UNDIFFERENTIATED |
| 123VLCC | VOLCANIC ROCKS (OLIGOCENE) |
| 123WRVR | WHITE RIVER FORMATION OR GROUP-SOUTH DAKOTA |
| 124ABSK | ABSAROKA VOLCANICS (EOCENE) |
| 124BVRD | BEAVERHEAD FORMATION (EOCENE - PALEOCENE) |
| 124CRDL | CRANDALL CONGLOMERATE-WYOMING |
| 124GLDV | GOLDEN VALLEY FORMATION-NORTH DAKOTA |
| 124GVSB | GOLDEN VALLEY FORMATION (OLIGOCENE-PALEOCENE) |
| 124KGBG | KINGSBURY CONGLOMERATE MEMBER (OF WASATCH FM) |
| 124KSNN | KISHENEHN FORMATION |
| 124LDCK | LOWLAND CREEK VOLCANICS |
| 124LVGS | LIVINGSTON FORMATION (EOCENE -CRETACEOUS) |
| 124PLNC | PLUTONIC ROCKS (EOCENE) |
| 124REES | REESE FORMATION-EOCENE |
| 124SDMS | SEDIMENTS (EOCENE) |
| 124SGCK | SAGE CREEK FORMATION |
| 124SPNX | SPHINX CONGLOMERATE |
| 124UDFD | EOCENE UNDIFFERENTIATED |
| 124VLCC | VOLCANICS (EOCENE) |
| 124WSTC | WASATCH FORMATION |
| 125ADCB | ANDERSON-DIETZ 1 COALS COMBINED - FT UNION FM |
| 125ADIB | ANDERSON-DIETZ INTERBURDEN - FT UNION FM |
| 125ADKB | ANDERSON-DIETZ1 CLINKER - FT UNION FM |
| 125ADKC | ANDERSON-DIETZ1 CLINKER AND COAL - FT UNION FM |
| 125ADOB | ANDERSON-DIETZ 1 AND 2 OVERBURDEN - FT UNION FM |
| 125ADUB | ANDERSON-DIETZ COAL UNDERBURDEN |
| 125ANCB | ANDERSON COAL OF THE FT UNION FORMATION |
| 125AND2 | ANDERSON-DIETZ 1 AND 2 COALS - FT UNION FM |
| 125ANUB | ANDERSON COAL UNDERBURDEN |
| 125BACB | BREWSTER-ARNOLD COAL - FT UNION FM |
| 125BAUB | BREWSTER-ARNOLD COAL UNDERBURDEN |
| 125BEAR | BEAR FORMATION |
| 125CDCB | C&D COAL |
| 125CDUB | C&D COAL UNDERBURDEN |
| 125CKCB | COOK COAL - FT UNION FM |
| 125CKUB | COOK COAL UNDERBURDEN |
| 125CNCB | CANYON COAL OF THE FT UNION FORMATION |
| 125CNOB | CANYON COAL OVERBURDEN - FT UNION FORMATION |
| 125CNUB | SUB-CANYON COAL SANDSTONE - FT UNION FM |
| 125CRCB | CARNEY COAL BED |
| 125D12K | DIETZ 1 AND 2 CLINKER AND COAL - FT UNION FM |
| 125D1CB | DIETZ 1 COAL OF THE FT UNION FORMATION |
| 125D1D2 | DIETZ 1 AND 2 COALS COMBINED - FT UNION FM |
| 125D23I | DIETZ 2 - 3 INTERBURDEN - FT UNION FM |
| 125D2CB | DIETZ 2 COAL OF THE FT UNION FORMATION |
| 125D3CB | DIETZ 3 COAL OF THE FT UNION FORMATION |
| 125DICB | DIETZ COAL OF THE FT UNION FORMATION |
| 125DIUB | DIETZ COAL UNDERBURDEN |
| 125ELCB | ELK COAL |
| 125ELUB | ELK COAL UNDERBURDEN |
| 125FGCB | FLOWERS-GOODALE COAL - FT UNION FM |
| 125FGOB | FLOWERS-GOODALE COAL OVERBURDEN - FT UNION FM |
| 125FGUB | FLOWERS-GOODALE COAL UNDERBURDEN - FT UNION FM |
| 125FRCB | FERRY COAL |
| 125FRUB | FERRY COAL UNDERBURDEN |
| 125FRUN | FORT UNION FORMATION |
| 125HRMN | HARMON LIGNITE OF THE TONGUE RIVER MEMBER |
| 125KNCB | KNOBLOCK COAL OF THE FT UNION FORMATION |
| 125KNOB | KNOBLOCK COAL OVERBURDEN SS - FT UNION FM |
| 125KNUB | KNOBLOCH COAL UNDERBURDEN - FT UNION FM |
| 125LDLW | LUDLOW MEMBER (OF FT UNION FM.) |
| 125LEBO | LEBO SHALE MEMBER (OF FT UNION FM.) |
| 125LKCB | LOWER KNOBLOCH COAL OF THE FORT UNION FORMATION |
| 125LNLY | LINLEY CONGLOMERATE (MEMBER OF THE FORT UNION FM) |
| 125LOCB | LOCAL COALS - FT UNION FM |
| 125MKCB | MCKAY COAL * FORT UNION FORMATION |
| 125MKOB | MCKAY OVERBURDEN-SANDSTONE - FT UNION FM |
| 125MMCB | MAMMOTH COAL OF THE FT UNION FM. |
| 125MMOB | MAMMOTH COAL OVERBURDEN - FT UNION FM |
| 125MMUB | SUB-MAMMOTH COAL UNITS - FT UNION FM. |
| 125MNCB | MONARCH COAL - FT UNION FM |
| 125NACB | NANCE COAL OF THE FT UNION FM |
| 125ODCB | ODELL COAL |
| 125ODUB | ODELL COAL UNDERBURDEN |
| 125OTCB | OTTER COAL OF THE FT UNION FM |
| 125OTUB | OTTER COAL UNDERBURDEN |
| 125PLNC | PLUTONIC ROCKS (PALEOCENE) |
| 125PWCB | PAWNEE COAL |
| 125PWUB | PAWNEE COAL UNDERBURDEN |
| 125RBCB | ROSEBUD COAL * FORT UNION FORMATION |
| 125RBMI | ROSEBUD-MCKAY INTERBURDEN * FT UNION FM. |
| 125RBOB | ROSEBUD OVERBURDEN SANDSTONE - FT UNION FM. |
| 125RLCB | ROLAND COAL - FT UNION FM |
| 125ROBN | ROBINSON COAL OF THE FORT UNION FORMATION |
| 125SAIB | SMITH/ANDERSON INTERBERDON - FT UNION FM. |
| 125SDMS | SEDIMENTS (PALEOCENE) |
| 125SMCB | SMITH COAL OF THE FORT UNION FORMATION |
| 125SMOB | SMITH COAL OVERBURDEN OF THE FORT UNION FORMATION |
| 125SNLB | SENTINEL BUTTE MEMBER (OF FT UNION FM.) |
| 125SRSL | SUB-ROBINSON SILT OF THE FT UNION FM. |
| 125SUMK | SUB-MCKAY SANDSTONE OF THE FT UNION FM. |
| 125SWCB | SAWYER COAL |
| 125SWUB | SAWYER COAL UNDERBURDEN |
| 125TGRV | TONGUE RIVER MEMBER (OF FT UNION FM.) |
| 125TLCK | TULLOCK MEMBER (OF FT UNION FM.) |
| 125TTCB | TERRET COAL - FT UNION FM |
| 125UDFD | PALEOCENE UNDIFFERENTIATED |
| 125VLCC | VOLCANICS (PALEOCENE) |
| 125WACB | WALL COAL - FT UNION FM |
| 125WAOB | WALL COAL OVERBURDEN - FT UNION FM |
| 125WAUB | WALL COAL UNDERBURDEN |
| 125WLCK | WILLOW CREEK FORMATION (LATE CRETACEOUS) |
| 200PLNC | PLUTONIC ROCKS (MESOZOIC) |
| 200SDMS | SEDIMENTS (UNDIFFERENTIATED) |
| 200UDFD | MESOZOIC UNDIFFERENTIATED |
| 200VLCC | VOLCANICS (MESOZOIC) |
| 210CRCS | USGS GEOLOGIC CODE (MEANING ?) |
| 210PLNC | PLUTONIC ROCKS (CRETACEOUS) |
| 210SDMS | SEDIMENTS (CRETACEOUS) |
| 210UDFD | CRETACEOUS UNDIFFERENTIATED |
| 210VLCC | VOLCANICS (CRETACEOUS) |
| 211ACRK | ASH CREEK SANDSTONE MEMBER (OF STEELE SHALE) |
| 211ADLM | ADEL MOUNTAIN VOLCANICS |
| 211ASPN | ASPEN SHALE |
| 211BDBT | BOULDER BATHOLITH |
| 211BDRV | BOULDER RIVER SS MEMBER (OF FRONTIER FM.) |
| 211BGEK | BIG ELK SANDSTONE (OF COLORADO GROUP) |
| 211BLCK | BULL CREEK SANDY LIMESTONE MEM (OF GREENHORN FM) |
| 211BLDB | USGS CODE (BOULDER BATHOLITH?) |
| 211BLFC | BELLE FOURCHE SHALE MEMBER (OF GRANEROS FM) |
| 211BMCK | BILLMAN CREEK FORMATION (OF LIVINGSTON GROUP) |
| 211BNTN | BENTON SHALE (OF COLORADO GROUP) |
| 211BRPW | BEARPAW SHALE |
| 211BSIN | BASIN SHALE |
| 211BVCK | BEAVER CREEK CHALKY MEMBER (OF NIOBRARA FM) |
| 211BWDN | BOWDOIN SANDSTONE |
| 211CBRL | COBERLY FORMATION (OF COLORADO GROUP) |
| 211CKDL | COKEDALE FORMATION (OF LIVINGSTON GROUP) |
| 211CLGT | CLAGGETT SHALE OR FORMATION |
| 211CLNC | CLANCY GRANODIORITE |
| 211CLRD | COLORADO SHALE OR FM. (OF COLORADO GROUP) |
| 211CODY | CODY SHALE |
| 211COGT | COLGATE SANDSTONE MEMBER (OF FOX HILLS FM.) |
| 211CONE | CONE CALCAREOUS MEM (OF MARIAS RIVER FM) |
| 211CRCK | CARTER CREEK FORMATION (OF COLORADO GROUP) |
| 211CRLL | CARLILE SHALE (OF COLORADO GROUP) |
| 211DBTL | IDAHO BATHOLITH |
| 211EGLE | EAGLE SANDSTONE |
| 211ELKB | ELK BASIN SANDSTONE MEMBER (OF TELEGRAPH CK FM) |
| 211ELKM | ELKHORN MOUNTAINS VOLCANICS |
| 211FHHC | FOX HILLS-HELL CREEK AQUIFER |
| 211FLWR | FLOWEREE MEMBER (OF MARIAS RIVER FM.) |
| 211FRDG | FERDIG SHALE MEMBER (OF MARIAS RIVER FM.) |
| 211FRHS | FORT HAYS LIMESTONE MEMBER (OF NIOBRARA FM) |
| 211FRNR | FRONTIER FORMATION |
| 211FSCL | FISH SCALE ZONE (IN GREENHORN FM.) |
| 211FWSK | FIRST WHITE SPECKS (IN NIOBRARA FM.) |
| 211FXHL | FOX HILLS FORMATION OR SANDSTONE |
| 211GMMN | GAMMON FERRUGINOUS MEMBER (OF PIERRE SHALE) |
| 211GRNR | GREENHORN LIMESTONE (OF COLORADO GROUP) |
| 211GROT | GROAT SANDSTONE BED (OF PIERRE SHALE) |
| 211GRRS | GRANEROS SHALE (OF COLORADO GROUP) |
| 211GSPK | GOLDEN SPIKE FM (OF MONTANA GROUP) |
| 211HLCK | HELL CREEK FORMATION |
| 211HLTR | HOLTER MEMBER (OF MARIAS RIVER FM.) |
| 211HPRS | HOPPERS FORMATION (OF LIVINGSTON GROUP) |
| 211HRSF | HORSETHIEF SANDSTONE (OF MONTANA GROUP) |
| 211JDRV | JUDITH RIVER FORMATION (OF MONTANA GROUP) |
| 211JENS | JENS FORMATION (OF COLORADO GROUP) |
| 211JREL | JUDITH RIVER-EAGLE FORMATIONS |
| 211KVIN | KEVIN SHALE MEMBER (OF MARIAS RIVER FM) |
| 211LHUD | LANCE-HELL CREEK UNDIFFERENTIATED |
| 211LNCE | LANCE FORMATION |
| 211LNNP | LENNEP SANDSTONE (OF MONTANA GROUP) |
| 211LVGS | UPPER CRETACEOUS LIVINGSTON GROUP |
| 211LVIS | LIVINGSTON IGNEOUS SERIES (OF LIVINGSTON GROUP) |
| 211LWIS | LEWIS SHALE OR FORMATION-WYOMING |
| 211MMHL | MONUMENT HILL BENTONITE MEMBER (OF PIERRE SH) |
| 211MNTN | MONTANA GROUP |
| 211MRCK | MINER CREEK FORMATION (OF LIVINGSTON GROUP) |
| 211MRRV | MARIAS RIVER FORMATION (OF COLORADO GROUP) |
| 211MSBY | MOSBY SANDSTONE MEMBER (OF WARM CREEK SHALE) |
| 211MTTN | MITTEN BLACK SHALE MEMBER (OF PIERRE SHALE) |
| 211MTTS | MEETEETSE FORMATION-WYOMING |
| 211MVRD | MESAVERDE FORMATION OR GROUP-WYOMING |
| 211NBRR | NIOBRARA FM. OR LIMESTONE (OF COLORADO GP) |
| 211PDRO | PEDRO BENTONITE BED (OF PIERRE SHALE) |
| 211PEAY | PEAY SANDSTONE MEMBER (OF FRONTIER FM.) |
| 211PINY | PINEY FORMATION-WYOMING |
| 211PIRR | PIERRE SHALE (OF MONTANA GROUP) |
| 211PLNC | PLUTONIC ROCKS (UPPER CRETACEOUS) |
| 211PLPS | PHILLIPS SANDSTONE |
| 211PRKM | PARKMAN SANDSTONE (OF MONTANA GROUP) |
| 211RDBD | RED BIRD SILTSTONE MEMBER (OF PIERRE SHALE) |
| 211SCGR | SCRATCHGRAVEL HILLS STOCK |
| 211SDAN | SEDAN FORMATION (UPPER CRETACEOUS) |
| 211SGBK | SAGE BREAKS SHALE MEMBER (OF NIOBRARA SHALE) |
| 211SGHN | SAGE HEN LIMESTONE (OF COLORADO SHALE) |
| 211SLPF | SULPHUR FLATS SS MEMBER (OF LIVINGSTON GROUP) |
| 211SMKH | SMOKY HILL CHALK MEMBER (OF NIOBRARA SHALE) |
| 211SMRV | ST. MARY RIVER FORMATION |
| 211SMSM | SLIM SAM FORMATION |
| 211SNNN | SHANNON SANDSTONE MBR. (OF CODY OR STEELE SH) |
| 211SPCK | SOAP CREEK BENTONITE BED (MEMBER OF FRONTIER FM) |
| 211SSPG | SHARON SPRINGS MEMBER (OF PIERRE SHALE) |
| 211SSSX | SUSSEX SANDSTONE MEMBER (OF CODY SHALE) |
| 211STEL | STEELE SHALE |
| 211SVLF | STONEVILLE FLATS LIMESTONE MEM (OF BELLE FOURCHE) |
| 211SWSK | SECOND WHITE SPECKS (IN GREENHORN LIMESTONE) |
| 211TBBT | TOBACCO ROOT BATHOLITH |
| 211TCLG | TORCHLIGHT SANDSTONE MEMBER (OF FRONTIER FM) |
| 211TMBS | TOMBSTONE SANDSTONE |
| 211TMDC | TWO MEDICINE FORMATION (OF MONTANA GROUP) |
| 211TPCK | TELEGRAPH CREEK FORMATION (OF MONTANA GROUP) |
| 211TPOT | TEAPOT SANDSTONE MEMBER (OF MESAVERDE FM.) |
| 211TRBT | TOBACCO ROOT BATHOLITH |
| 211TRNR | TURNER SANDY MEMBER (OF CARLILE SHALE) |
| 211UDFD | UPPER CRETACEOUS UNDIFFERENTIATED |
| 211UNVL | UNIONVILLE GRANODIORITE |
| 211VLCC | VOLCANICS (UPPER CRETACEOUS) |
| 211VRGL | VIRGELLE SANDSTONE MEMBER (OF EAGLE SANDSTONE) |
| 211WLCK | WALL CREEK SANDSTONE MEMBER (OF FRONTIER FM) |
| 211WMCK | WARM CREEK SHALE (OF COLORADO GROUP) |
| 217ALBN | ABINO SHALE MEMBER (OF THERMOPOLIS SHALE) |
| 217AMFK | AMERICAN FORK FORMATION |
| 217BCKF | BLACKLEAF FORMATION (OF COLORADO GROUP) |
| 217BILD | BOW ISLAND SANDSTONE |
| 217BLCD | BASAL COLORADO SILTSTONE (OR DAKOTA SILT) |
| 217BLGR | BOOTLEGGER MEMBER (OF BLACKLEAF FM.) |
| 217BRDD | BIRDHEAD SANDSTONE MEMBER (OF THERMOPOLIS FM) |
| 217CBNK | CUT BANK SANDSTONE |
| 217CLSN | CHILSON MEMBER (OF LAKOTA FM.) |
| 217CLSP | CLAY SPUR BENTONITE BED (OF MOWRY SHALE) |
| 217CLVL | CLOVERLY FORMATION |
| 217CPRN | CYPRIAN SANDSTONE MEMBER (OF THERMOPOLIS SH) |
| 217DKBG | DUNKLEBERG MEMBER (OF BLACKLEAF FM.) |
| 217DKOT | DAKOTA SANDSTONE FORMATION OR GROUP |
| 217DRLG | DARLING SANDSTONE |
| 217FCCK | FIRST CAT CREEK SANDSTONE (BASE OF COLORADO GP) |
| 217FLOD | FLOOD SHALE MEMBER (OF BLACKLEAF FM.) |
| 217FLRV | FALL RIVER FORMATION (OF INYAN KARA GROUP) |
| 217FUSN | FUSON MEMBER (OF LAKOTA FM.) |
| 217GRBL | GREYBULL SANDSTONE MEMBER (OF CLOVERLY FM) |
| 217HINS | HINES MEMBER (OF CLOVERLY FM.) |
| 217INKR | INYAN KARA GROUP |
| 217KOTN | KOOTENAI FORMATION |
| 217LKOT | LAKOTA SANDSTONE (OF INYAN KARA GROUP) |
| 217LLSP | LITTLE SHEEP MEMBER (OF CLOVERLY FM.) |
| 217LPTN | LUPTON SAND (OF KOOTENAI FM) (2ND CAT CREEK SAND) |
| 217MDDY | MUDDY SANDSTONE MEMBER (OF THERMOPOLIS SHALE) |
| 217MLTN | MOULTON SANDSTONE |
| 217MSSR | MOSSER SANDSTONE |
| 217MWRY | MOWRY SHALE (OF COLORADO GROUP) |
| 217NCSL | NEWCASTLE SANDSTONE MEMBER (OF GRANEROS SHALE) |
| 217PLNC | PLUTONIC ROCKS (LOWER CRETACEOUS) |
| 217PRYR | PRYOR CONGLOMERATE MEMBER (OF CLOVERLY FM) |
| 217RSTY | RUSTY BEDS (IN THERMOPOLIS SHALE) |
| 217SBRS | SUNBURST SANDSTONE |
| 217SCCK | SECOND CAT CREEK SANDSTONE (OF KOOTENAI FM) |
| 217SDMS | SEDIMENTS (LOWER CRETACEOUS) |
| 217SKCK | SKULL CREEK SHALE MEMBER (OF GRANEROS SHALE) |
| 217TCCK | THIRD CAT CREEK SANDSTONE (BASAL KOOTENAI FM) |
| 217TFHL | TAFT HILL MEMBER (OF BLACKLEAF FM.) |
| 217TMPL | THERMOPOLIS SHALE |
| 217UDFD | LOWER CRETACEOUS UNDIFFERENTIATED |
| 217VGHN | VAUGHN MEMBER (OF BLACKLEAF FM.) |
| 217VKNG | VIKING SANDSTONE-CANADA |
| 217VLCC | VOLCANICS (LOWER CRETACEOUS) |
| 220SUDE | SAUDE FORMATION (JURASSIC-TRIASSIC) |
| 220UDFD | JURASSIC UNDIFFERENTIATED |
| 221BRDL | BRINDLEY SANDSTONE (OF MORRISON FM.) |
| 221CSPG | CANYON SPRINGS SANDSTONE MEM (OF SUNDANCE FM) |
| 221ELLS | ELLIS GROUP |
| 221HLTT | HULETT SANDSTONE MEMBER (OF SUNDANCE FM) |
| 221LAK | LAK MEMBER (OF SUNDANCE FM.) |
| 221MRSN | MORRISON FORMATION |
| 221RDTR | REDWATER SHALE MEMBER (OF SUNDANCE FM.) |
| 221RRDN | RIERDON FORMATION (OF ELLIS GROUP) |
| 221SKBV | STOCKADE BEAVER SHALE MEMBER (OF SUNDANCE FM) |
| 221SNDC | SUNDANCE FORMATION |
| 221SWFT | SWIFT FORMATION (OF ELLIS GROUP) |
| 221UDFD | UPPER JURASSIC UNDIFFERENTIATED |
| 221VGRD | VANGUARD FORMATION |
| 224BOWS | BOWES MEMBER (OF PIPER FM.) |
| 224FRMN | FIREMOON LIMESTONE MEMBER (OF PIPER FM.) |
| 224GPSP | GYPSUM SPRING FORMATION |
| 224KLIN | KLINE MEMBER (OF NESSON FM.) |
| 224NSSN | NESSON FORMATION |
| 224PCRD | PICARD MEMBER (OF NESSON FM.) |
| 224PIPR | PIPER FORMATION |
| 224POE | POE MEMBER (OF NESSON FM.) |
| 224STTH | SAWTOOTH FORMATION (OF ELLIS GROUP) |
| 224TMPC | TAMPICO MEMBER (OF PIPER FM.) |
| 224UDFD | MIDDLE JURASSIC UNDIFFERENTIATED |
| 230ALCV | ALCOVA LIMESTONE MEMBER (OF CHUGWATER FM.) |
| 230BWLR | BOWLER FORMATION |
| 230CGTR | CHUGWATER FORMATION |
| 230CRMN | CROW MTN SANDSTONE MEMBER (OF CHUGWATER FM) |
| 230GSEG | GOOSE EGG FORMATION |
| 230RDPK | RED PEAK MEMBER (OF CHUGWATER FM.) |
| 230SPRF | SPEARFISH FORMATION |
| 230UDFD | TRIASSIC UNDIFFERENTIATED |
| 230WDSD | WOODSIDE SHALE |
| 231PPAG | POPO AGIE MEMBER OF CHUGWATER FM. |
| 231UDFD | UPPER TRIASSIC UNDIFFERENTIATED |
| 237DNDY | DINWOODY FORMATION |
| 237TYNS | THAYNES LIMESTONE FORMATION OR GROUP |
| 237UDFD | LOWER TRIASSIC UNDIFFERENTIATED |
| 237WDSD | WOODSIDE FORMATION SILTSTONE OR REDBEDS |
| 300PLNC | PLUTONIC ROCKS (PALEOZOIC) |
| 300SDMS | SEDIMENTS (PALEOZOIC) |
| 300UDFD | PALEOZOIC UNDIFFERENTIATED |
| 300VLCC | VOLCANICS (PALEOZOIC) |
| 310ERVY | ERVAY MEMBER OF TONGUE (OF PHOSPHORIA FM) |
| 310FRNS | FRANSON MEMBER OR TONGUE (OF PARK CITY FM) |
| 310GRDR | GRANDEUR MEMBER (OF PARK CITY FM.) |
| 310MDPK | MEADE PEAK PHOSPHATIC SHALE MBR. (OF PHOSPORIA FM) |
| 310PNSL | PINE SALT MEMBER (OF SPEARFISH FM.) |
| 310PRKC | PARK CITY FORMATION OR GROUP |
| 310PSPR | PHOSPHORIA FORMATION |
| 310REX | REX CHERT MEMBER (OF PHOSPHORIA FM.) |
| 310RTRT | RETORT PHOSPHATIC SHALE MBR. (OF PHOSPHORIA FM) |
| 310SDRN | SHEDHORN SANDSTONE |
| 310TOSI | TOSI CHERT MEMBER OR TONGUE (OF PHOSPHORIA FM) |
| 310UDFD | PERMIAN UNDIFFERENTIATED |
| 317MNKT | MINNEKAHTA LIMESTONE MEMBER (OF GOOSE EGG FM) |
| 317OPCH | OPECHE SHALE |
| 317UDFD | LOWER PERMIAN UNDIFFERENTIATED |
| 320AKBC | ALASKA BENCH LIMESTONE OF AMSDEN GROUP |
| 320AMSD | AMSDEN GROUP |
| 320BGLC | BEAR GULCH LIMESTONE MEMBER (OF TYLER FM.) |
| 320CMCK | CAMERON CREEK MEMBER (OF TYLER FM.) |
| 320DRWN | DARWIN SANDSTONE (OF AMSDEN GROUP) |
| 320DVPK | DEVILS POCKET FORMATION (OF AMSDEN GROUP) |
| 320MNLS | MINNELUSA SANDSTONE OR FORMATION |
| 320QDRN | QUADRANT QUARTZITE |
| 320SNSC | STONEHOUSE CANYON MEMBER (OF TYLER FM.) |
| 320TSLP | TENSLEEP SANDSTONE |
| 320TYLR | TYLER FORMATION (OF AMSDEN GROUP) |
| 320UDFD | PENNSYLVANIAN UNDIFFERENTIATED |
| 330BKKN | BAKKEN FORMATION |
| 330CLRF | CASTLE REEF DOLOMITE (OF MADISON GROUP) |
| 330EGLD | ENGLEWOOD FORMATION |
| 330HNNH | HANNAH LIMESTONE |
| 330MDLC | MIDDLE CANYON FORMATION (OF WHITE KNOB GROUP) |
| 330MDSN | MADISON GROUP OR LIMESTONE |
| 330MLGN | MILLIGAN FORMATION |
| 330SCPK | SCOTT PEAK FORMATION (OF WHITE KNOB GROUP) |
| 330SCRK | SOUTH CREEK FORMATION (OF WHITE KNOB GROUP) |
| 330SRCN | SURRETT CANYON FORMATION (OF WHITE KNOB GROUP) |
| 330SRVR | SUN RIVER MEMBER (OF CASTLE REEF DOLOMITE) |
| 330UDFD | MISSISSIPPIAN UNDIFFERENTIATED |
| 330WKNB | WHITE KNOB LIMESTONE OR GROUP - IDAHO |
| 331A | 'A' ZONE (OF CHARLES FORMATION) |
| 331B | 'B' ZONE (OF CHARLES FORMATION) |
| 331BGSN | BIG SNOWY GROUP |
| 331C | 'C' ZONE (OR 'BERENTSON' ZONE) (OF CHARLES FM) |
| 331CRLS | CHARLES FORMATION (OF MADISON GROUP) |
| 331HETH | HEATH FORMATION OR SHALE OF BIG SNOWY GROUP |
| 331KBBY | KIBBEY SANDSTONE (OF BIG SNOWY GROUP) |
| 331MIDL | 'MIDALE' ZONE (OF CHARLES FORMATION) |
| 331OTTR | OTTER FORMATION (OF BIG SNOWY GROUP) |
| 331RCHY | RICHEY SHALE ZONE (IN CHARLES FM.) |
| 331UDFD | UPPER MISSISSIPPIAN UNDIFFERENTIATED |
| 337ALMN | ALLEN MOUNTAIN LIMESTONE (OF MADISON GROUP) |
| 337CNDC | COTTONWOOD CANYON MEMBER (OF LODGEPOLE LMST) |
| 337D | D' ZONE (OF MISSION CANYON FM.) |
| 337DNLK | DEAN LAKE CHERT MEMBER (OF MADISON LIMESTONE) |
| 337EXSH | EXSHAW SHALE |
| 337LCFC | LITTLE CHIEF CANYON MBR. OF LODGEPOLE LIMESTONE |
| 337LDGP | LODGEPOLE LIMESTONE OR FM. (OF MADISON GP) |
| 337MNRM | MONITOR MTN. LIMESTONE MEMBER (OF MADISON GP) |
| 337MSNC | MISSION CANYON LIMESTONE (OF MADISON GROUP) |
| 337PHSP | PAHASAPA LIMESTONE - SOUTH DAKOTA |
| 337PINE | PAINE SHALE MEMBER (OF LODGEPOLE FM.) |
| 337RONY | ROONEY CHERT MEMBER (OF MADISON LIMESTONE) |
| 337SLVP | SILVERTIP CONGLOMERATE MEMBER (OF MADISON GP) |
| 337SPNG | SAPPINGTON FORMATION |
| 337SYPO | SAYPO LIMESTONE MEMBER (OF MADISON LIMESTONE) |
| 337TRFK | THREE FORKS SHALE LIMESTONE OR FORMATION |
| 337UDFD | LOWER MISSISSIPPIAN UNDIFFERENTIATED |
| 337WDRS | WOODHURST LIMESTONE MEMBER (OF LODGEPOLE FM) |
| 340UDFD | DEVONIAN UNDIFFERENTIATED |
| 341BRDB | BIRDBEAR MEMBER (OF JEFFERSON LIMESTONE) |
| 341BVLK | BEAVERHILL LAKE GROUP OR FORMATION |
| 341CPLK | COOPERS LAKE LIMESTONE MEMBER (OF JEFFERSON FM) |
| 341DPRW | DUPEROW FORMATION (OF JEFFERSON GROUP) |
| 341DRBY | DARBY FORMATION |
| 341GLCK | GLEN CREEK SHALE MEMBER (OF JEFFERSON LIMESTONE) |
| 341GRDV | GRAND VIEW DOLOMITE - IDAHO |
| 341JFRS | JEFFERSON LIMESTONE |
| 341LGGC | LOGAN GULCH MEMBER (OF THREE FORKS FM.) |
| 341LNBT | LONE BUTTE LIMESTONE MEMBER (OF JEFFERSON FM) |
| 341NSKU | NISKU FORMATION |
| 341PTLC | POTLATCH FORMATION OR ANHYDRITE |
| 341SPDB | SPOTTED BEAR LIMESTONE MEMBER (OF JEFFERSON GP) |
| 341SRRV | SOURIS RIVER FORMATION |
| 341TRDN | TRIDENT MEMBER (OF THREE FORKS FORMATION) |
| 341UDFD | UPPER DEVONIAN UNDIFFERENTIATED |
| 341UNON | UNION SHALE |
| 341WDBD | WOODBEND FORMATION - ALBERTA |
| 341WRDG | WHITE RIDGE LIMESTONE MEMBER (OF JEFFERSON GP) |
| 344ASRN | ASHERN FORMATION (OF ELK POINT GROUP) |
| 344BRTB | BEARTOOTH BUTTE FORMATION |
| 344DSNB | DAWSON BAY FORMATION |
| 344ELKP | ELK POINT GROUP |
| 344MYWD | MAYWOOD FORMATION |
| 344PRIR | PRAIRIE EVAPORITE FORMATION (OF ELK POINT GP) |
| 344UDFD | MIDDLE AND LOWER DEVONIAN UNDIFFERENTIATED |
| 344WPGS | WINNEPEGOSIS FORMATION (OF ELK POINT GROUP) |
| 350IRLK | INTERLAKE FORMATION |
| 350LKTN | LAKETOWN DOLOMITE - UTAH |
| 350UDFD | SILURIAN UNDIFFERENTIATED |
| 360UDFD | ORDOVICIAN UNDIFFERENTIATED |
| 361BGRN | BIGHORN DOLOMITE |
| 361GNTN | GUNTON MEMBER (OF STONY MOUNTAIN FM.) |
| 361HRDG | HARDING SANDSTONE (OF BIGHORN DOLOMITE) |
| 361LIGH | LEIGH DOLOMITE MEMBER (OF BIGHORN DOLOMITE) |
| 361LNDR | LANDER SANDSTONE (OF BIGHORN DOLOMITE) |
| 361RDRV | RED RIVER FORMATION (OF BIGHORN GROUP) |
| 361SNMN | STONY MOUNTAIN FORMATION (OF BIGHORN GROUP) |
| 361STGN | STOUGHTON MEMBER (OF STONY MOUNTAIN FM.) |
| 361UDFD | UPPER ORDOVICIAN UNDIFFERENTIATED |
| 361WHTD | WHITEWOOD DOLOMITE |
| 364ALDN | ALADDIN SANDSTONE - SOUTH DAKOTA |
| 364ICBX | ICE BOX SHALE - SOUTH DAKOTA |
| 364KNKC | KINNIKINIC QUARTZITE |
| 364RGCK | ROUGHLOCK SILTSTONE - SOUTH DAKOTA |
| 364WNPG | WINNIPEG FORMATION |
| 370BKSP | BUCK SPRING FORMATION |
| 370CMBR | CAMBRIAN UNDIFFERENTIATED |
| 370HMRK | HASMARK FORMATION OR DOLOMITE |
| 371DDWD | DEADWOOD FORMATION |
| 371DRBR | DEARBORN LIMESTONE |
| 371DRCK | DRY CREEK SHALE |
| 371DUNR | DU NOIR LIMESTONE MEMBER (OF GALLATIN LIMESTONE) |
| 371DVLG | DEVILS GLENN DOLOMITE |
| 371GLTN | GALLATIN GROUP |
| 371GVCK | GROVE CREEK MEMBER (OF SNOWY RANGE FM.) |
| 371OPDR | OPEN DOOR LIMESTONE (OF GALLATIN LIMESTONE) |
| 371PLGM | PILGRIM LIMESTONE OR DOLOMITE |
| 371RDLN | RED LION FORMATION |
| 371SNRG | SNOWY RANGE FORMATION (OF GALLATIN GROUP) |
| 371YOGO | YOGO LIMESTONE |
| 374ALPR | ALPRESTON QUARTZITE |
| 374DCNN | DEATH CANYON LIMESTONE MEMBER (OF GROS V |
| 374DMNN | DAMNATION LIMESTONE |
| 374EMRS | EMERSON FORMATION |
| 374FLTD | FLATHEAD QUARTZITE OR SANDSTONE |
| 374GRDN | GORDON SHALE |
| 374GRVR | GROS VENTRE FORMATION |
| 374MGHR | MEAGHER LIMESTONE |
| 374PARK | PARK SHALE OR ARGILLITE |
| 374PGOD | PAGODA LIMESTONE |
| 374PNGN | PENTAGON SHALE |
| 374SCBK | SWITCHBACK SHALE |
| 374SLVH | SILVER HILL FORMATION |
| 374TLDN | TILDEN FORMATION |
| 374WLSY | WOLSEY SHALE OR FORMATION |
| 377STMB | STEAMBOAT LIMESTONE |
| 377UDFD | LOWER CAMBRIAN UNDIFFERENTIATED |
| 400AHRN | AHORN QUARTZITE |
| 400ALTN | ALTYN LIMESTONE |
| 400APCK | APPLE CREEK FORMATION |
| 400APKN | APPEKUNNY FORMATION |
| 400BCKF | BLACKFOOT FORMATION |
| 400BCRD | BOUCHARD FORMATION (OF MISSOULA GROUP) |
| 400BELT | BELT SUPERGROUP |
| 400BNNR | BONNER QUARTZITE (OF MISSOULA GROUP) |
| 400BURK | BURKE FORMATION (OF RAVALLI GROUP) |
| 400CMBL | CHAMBERLAIN SHALE |
| 400COOK | COOK GRANITE |
| 400CPCK | CAMP CREEK GROUP |
| 400CYUS | CAYUSE LIMESTONE |
| 400EMPR | EMPIRE FORMATION |
| 400GCRK | GOOSE CREEK GRANITE |
| 400GRNL | GRINNELL FORMATION (OF RAVALLI GROUP) |
| 400GRRG | GARNET RANGE QUARTZITE OR FORMATION |
| 400GRRM | GREENHORN MOUNTAIN QUARTZITE |
| 400GRSN | GREYSON SHALE |
| 400GTWY | GATEWAY FORMATION |
| 400HDLY | HOADLEY FORMATION |
| 400HELN | HELENA DOLOMITE |
| 400HLGT | HELLGATE QUARTZITE MEM (OF MILLER PEAK ARGILLITE) |
| 400KNTL | KINTLA ARGILLITE (OF MISSOULA GROUP) |
| 400LBBY | LIBBY FORMATION (OF MISSOULA GROUP) |
| 400LHOD | LAHOOD FORMATION |
| 400LMHI | LEMHI QUARTZITE - IDAHO |
| 400LUPN | LUPINE QUARTZITE (OF MISSOULA GROUP) |
| 400MCMR | MCNAMARA ARGILLITE OR FM. (OF MISSOULA GP) |
| 400MCRB | MIDDLE BELT CARBONATE |
| 400MLPK | MILLER PEAK ARGILLITE OR FM (OF MISSOULA GROUP) |
| 400MMPC | METAMORPHIC ROCKS |
| 400MRSH | MARSH FORMATION (OF MISSOULA GROUP) |
| 400MSSL | MISSOULA GROUP |
| 400NHRT | NEIHART QUARTZITE |
| 400NLND | NEWLAND FORMATION OR LIMESTONE |
| 400PIGN | PIEGAN GROUP |
| 400PLCR | PILCHER QUARTZITE (OF MISSOULA GROUP) |
| 400PRCD | PRICHARD FORMATION OR SLATE |
| 400PRCL | PURCELL BASALT (OF MISSOULA GROUP) |
| 400RRBR | ROCK RABBIT RIDGE QUARTZITE |
| 400RVLL | RAVALLI GROUP |
| 400RVTT | REVETT FORMATION (OF RAVALLI GROUP) |
| 400SIYH | SIYEH LIMESTONE (OF PIEGAN GROUP) |
| 400SLWY | SLOWAY FORMATION (OF MISSOULA GROUP) |
| 400SPKN | SPOKANE SHALE |
| 400SPRC | SPRUCE FORMATION (OF MISSOULA GROUP) |
| 400SPRD | SHEPARD FORMATION (OF MISSOULA GROUP) |
| 400SRGS | ST REGIS FORMATION (OF RAVALLI GROUP) |
| 400STRP | STRIPED PEAK FORMATION (OF MISSOULA GROUP) MID PRO |
| 400SWGR | SWAUGER QUARTZITE - IDAHO |
| 400UDFD | PRECAMBRIAN UNDIFFERENTIATED |
| 400WLLC | WALLACE FORMATION (OF PIEGAN GROUP) |
| 500CRCK | CHERRY CREEK GROUP - PRE-BELT |
| 500GNSC | GNEISS AND SCHIST (EARLY PROTEROZOIC OR ARCHEAN) |
| 500PCMB | PRECAMBRIAN (EARLY PROTEROZOIC OR ARCHEAN) |
| 500PONY | PONY SERIES - PRE-BELT |
| 500PRBL | PRE-BELT |
| 500STLR | STILLWATER COMPLEX (ARCHEAN) |