Fusso, L.A.Petersen, E.I.Emond, A.M.EON Geosciences Inc.2026digital, dataGeophysical ReportGPR 2026-2Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys17 phttps://doi.org/10.14509/31804Kuskokwim airborne magnetics and radiometric geophysical survey, McGrath, Alaska, Geophysical Report 2026-2, covers parts of the Norton Bay, Nulato, Ruby, Unalakleet, Ophir, Medfra, Holy Cross, Iditarod, and McGrath quadrangles. EON Geosciences Inc. collected magnetic and radiometric data with four fixed wing aircraft from June 23 to September 5, 2024, then from June 14 to July 26, 2025. A total of 86,319 line-kilometers were acquired. Magnetic data were collected with a Geometrics G-822A cesium-vapour split-beam sensor; Radiometric data were collected with two (2) Radiation Solutions RS-500 series multi-channel gamma-ray spectrometers, model RSX-5, with 512 channels, for a total crystal volume of 33.6 liters downward-looking and 8.4 upward-looking (for atmospheric radon detection). The McGrath survey was flown with a line spacing of 400 meters (m) and a nominal ground clearance of 100 m. The data from the McGrath airborne magnetic and radiometric geophysical survey will improve understanding of the geology and mineral potential and promote resource exploration of the central Kuskokwim River region of Alaska. These data are provided as a Geophysical Report under an open end-user license and are available on the DGGS website https://doi.org/10.14509/31804.The purpose of this report is to provide airborne magnetic and radiometric geophysical data to improve understanding of the geology and mineral potential of the central Kuskokwim River region and to support resource exploration efforts. These high-resolution data help identify concealed lithologic contacts, structural features, and alteration zones associated with gold and other metallic mineral deposits.>ascii_data: ASCII format line data, other ASCII data >databases_geosoft: Geosoft format database of final line data, other Geosoft format databases >documents: Project report, calibration reports >grids_geosoft: Oasis montaj Geosoft GRD format gridded data >grids_tif: Geographically registered data value rasters of gridded data, GeoTiff format >kmz: Keyhole Markup Language (KML) kmz archive files of project data. Viewable on Google Earth and other compatible programs >maps_pdf: Printable and geographically registered maps in pdf format. >vector_data: Line path and survey boundary in Esri shapefile (shp) format20242025ground conditionCompleteNone planned-159.738208-152.91571764.08068161.970973ISO 19115 Topic CategorygeoscientificInformationAlaska Division of Geological & Geophysical SurveysAeromagneticAeromagnetic DataAeromagnetic MapAeromagnetic SurveyAirborne Geophysical SurveyAnalytic SignalBedrock GeologyCritical MineralsDGGSEarth MRIEconomic GeologyEconomic StudyFixed Wing SurveyGeologyGeophysical MapGeophysical SurveyGeophysicsGeophysics Search TagGridded DataMagnetic ContoursMagnetic DataMagnetic SurveyMagneticsMineral AssessmentMineral Deposit ModelsMineral DevelopmentMineral ExplorationMineral ResourcesMineralsRadiometric SurveyRadiometricsRemote SensingAlaska Division of Geological & Geophysical SurveysAniak Mining DistrictAnvik Mining DistrictAppel MountainBanner CreekBarnhard CreekBasin CreekBear CreekBear Island LakeBeaver CreekBelle CreekBerry LakeBig CreekBig RiverBilly Goat CreekBismarck CreekBismark CreekBlack CreekBlack MountainBlack RiverBlackwater CreekBonanza CreekBonanza FlatsBonnie CreekBoob CreekBoston CreekBoulder CreekBridge CreekBroken Snowshoe CreekBryan CreekButte CreekCache CreekCalifornia CreekCamp CreekCandle CreekCandle PlacerCanyon CreekCaribou CreekCarl CreekCash CreekChicken CreekChicken MountainClear CreekClearwater CreekCoffee CreekColorado CreekCottonwood LakeCrawson LakeCripple CreekCripple LandingCrooked CreekDeacons LandingDeadwood CreekDeep CreekDikemanDiscoveryDishna RiverDoherty CreekDome CreekDominion CreekDonlin CreekEagle CreekEsperanto CreekEsperanto Placer MineFairbanks CreekFarewell LandingFinland CreekFire CreekFlatFlat CreekFolgerFolger CreekFourmile CreekFourmile LakeFox CreekFranklin CreekFrisco CreekFrying Pan CreekGalatea CreekGentian CreekGeorge RiverGlacier CreekGraham CreekGranite CreekGranite MountainGrayling CreekGuitar LakeHalfway MountainHappy CreekHarrell IslandHenry CreekHickey CreekHighpower CreekHomestake CreekHook LakeHorsefly CreekHunch CreekHunch MountainHurst CreekIditarodIditarod Mining DistrictIditarod RiverIllinois CreekInnoko Mining DistrictInnoko RiverIron CreekIvy CreekJohn Reek CreekJulian CreekJulie CreekKaiyuh Mining DistrictKaiyuh MountainsKatlitna RiverKhotol RiverKing CreekKuskokwim RiverLake CreekLedge CreekLittle Caribou CreekLittle CreekLone Jim MountainLonesome HillsLong CreekLookout MountainLost RiverLower Telida LakeMadison CreekMadison MountainMammoth CreekMartin CreekMastodon CreekMcGrathMcGrath Mining DistrictMeadow CreekMedfraMedicine CreekMichigan CreekMinnie CreekMisdiMontana CreekMoore CreekMoose CreekMorgan IslandMosquito MountainMud RiverMunther CreekMurray CreekMystery CreekNetletna RiverNikolaiNixon ForkNowitna RiverNunivak BarNunsatuk RiverOphir CreekOtter CreekOur CreekPeary CreekPedro CreekPilot CreekPoison CreekPontag CreekPoorman CreekPorcupine RidgePorphyry HillPrince CreekReed LakeReindeer RiverRoundabout MountainRuby CreekRuby Mining DistrictSaddle MountainSalmonberry LakeScandinavian CreekScow Harry CreekSelatna MountainSelatna RiverShagelukShageluk LakeShoaty CreekShoaty MountainSilver CreekSkookum CreekSlate CreekSlow CreekSmith CreekSmittys LakeSoda CreekSpruce Lined CreekStarr CreekStink CreekSugarloaf MountainSulukna RiverSunrise CreekSunset CreekSusulatna RiverTaft CreekTakotna RiverTango CreekTatalina RiverTelidaTimber CreekTolstoi CreekTonclonkna CreekTonclonukna CreekTonlhona CreekTonzona RiverTowahmina LakeTrail CreekTravis CabinTwin Island CreekTwomile CreekUyakturok CreekVinasaleVinasale MountainWabash CreekWapoo CreekWeir IslandWidgeon CreekWillow CreekWilson CreekWilson LakeWindy CreekWolf MountainWolverine CreekYukon RiverZimmerman CreekThis report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.Alaska Division of Geological & Geophysical SurveysGIS Managermailing and physical

3354 College Rd

FairbanksAK99709-3707USA907-451-5020dggsgis@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysThis work was funded by the United States Geological Survey Earth Mapping Resources Initiative (Earth MRI) grants G22AC00475 and G23AC00408. The authors thank Eon Geosciences for their expertise in geophysical data collection. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.Emond, A.M.MPX Geophysics LTD2023Geophysical ReportGPR 2023-1Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/31087Emond, A.M.Fusso, L.A.Geotech Ltd.2024Geophysical ReportGPR 2024-1Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys4 phttps://doi.org/10.14509/31094Fusso, L.A.Petersen, E.I.New Resolution Geophysics, USA2025Geophysical ReportGPR 2025-5Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys18 phttps://doi.org/10.14509/31724Fusso, L.A.Petersen, E.I.Emond, A.M.EON Geosciences Inc.2025Geophysical ReportGPR 2025-3Fairbanks, Alaska, United StatesAlaska Division of Geological & Geophysical Surveys18 phttps://doi.org/10.14509/31493Geophysical data were acquired according to the contractor, contract, and request-for-proposals specifications. For additional detail about survey parameters, see the accompanying project report available in the documents directory of this data distribution package.Data were supplied by providers in accordance with DGGS contract requirements (see accompanying project report). The originating coordinate system was retained for all publication products.The dataset provides processed geophysical and positional data for the entire survey extent.Station coordinates were positioned using a real-time or post-processed corrected differential GPS.Not applicableData acquisition - EON Geosciences Inc. collected magnetic and radiometric data with four fixed wing aircraft from June 23 to September 5, 2024, then from June 14 to July 26, 2025. A total of 86,319 line-kilometers were acquired. Magnetic data were collected with a Geometrics G-822A cesium-vapour split-beam sensor; Radiometric data were collected with two (2) Radiation Solutions RS-500 series multi-channel gamma-ray spectrometers, model RSX-5, with 512 channels, for a total crystal volume of 33.6 liters downward-looking and 8.4 upward-looking (for atmospheric radon detection). The McGrath survey was flown with a line spacing of 400 meters (m) and a nominal ground clearance of 100 m.2025Data cataloged for archival and publication - Final data were published and archived by DGGS.2026rasterUniversal Transverse Mercator40.999600-1590500000.0000000coordinate pair.00000001.00000001MetersWGS84WGS 846378137298.257223563ascii_dataASCII format line data, other ASCII dataEON Geosciences Inc.ascii_datadatabases_geosoftGeosoft format database of final line data, other Geosoft format databasesEON Geosciences Inc.databases_geosoftdocumentsProject report, calibration reportsEON Geosciences Inc. and Alaska Division of Geological & Geophysical Surveys (DGGS)documentsgrids_geosoftOasis montaj Geosoft GRD format gridded dataEON Geosciences Inc. and Alaska Division of Geological & Geophysical Surveys (DGGS)grids_geosoftgrids_tifGeographically registered data value rasters of gridded data, GeoTiff formatAlaska Division of Geological & Geophysical Surveys (DGGS)grids_tifkmzKeyhole Markup Language (KML) kmz archive files of project data. Viewable on Google Earth and other compatible programsAlaska Division of Geological & Geophysical Surveys (DGGS)kmzmaps_pdfPrintable and geographically registered maps in pdf format.EON Geosciences Inc.maps_pdfvector_dataLine path and survey boundary in Esri shapefile (shp) formatAlaska Division of Geological & Geophysical Surveys (DGGS)vector_dataState of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveysmailing and physical

3354 College Road

FairbanksAK99709-3707USA907-451-5020907-451-5050dggspubs@alaska.gov8 am to 4:30 pm, Monday through Friday, except State holidaysPlease view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.GPR 2026-2The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.see http://dx.doi.org/10.14509/31804GeoTiff, ESRI shapefile, Geosoft binary grid (GRD), Microsoft Office documents, PDF (with or without georeferencing), ER Mapper ERS, ASCII text files (including CSV), Geosoft database, AutoCAD DXF, Geosoft plot file (PLT), digital images (multiple formats), georeferenced photos (multiple formats), Geosoft ASCII XYZ, Geosoft ASCII files (PLY, i0, EXP), and KMZ.20260616Airborne electromagnetic geophysical survey data compilationhttp://dx.doi.org/10.14509/31804Free download20260616Simone Montaynemailing and physical

3354 College Road

FairbanksAK99709-3707USA907-451-5020FGDC Content Standard for Digital Geospatial MetadataFGDC-STD-001-1998If the user has modified this metadata file in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent this metadata file, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys.http://www.dggs.alaska.gov/metadata/dggs.extdggs metadata extensions