Oregon Department of Geology and Mineral Industries 2026 Assay Returns, Oregon. tabular digital data Oregon Department of Geology and Mineral Industries Digital Data MILO-4 Portland, Oregon, USA Oregon Department of Geology and Mineral Industries https://www.oregon.gov/dogami/pages/default.aspx Oregon Department of Geology and Mineral Industries 2026 Mineral Information Layer for Oregon-Release 4 (MILO-4) Release 4 Oregon Department of Geology and Mineral Industries Digital Data MILO-4 Portland, Oregon, USA Oregon Department of Geology and Mineral Industries https://www.oregon.gov/dogami/pages/default.aspx The Mineral Information Layer for Oregon-Release 4 (MILO-Release 4) is a geospatial database that stores and manages information regarding Oregon's mineral occurrences, prospects, and mines; it is the primary way in which the State extracts, researches, and displays its available historical mining and mineral resource information. This table contains fields for client information (e.g., name, address, citizenship), sample location information (e.g., county, mining district, township, range, section, and the analysis desired), and sample type (e.g., channel, grab, description; nature of sample or mineralization), which were provided by the client at the time of submittal to DOGAMI. Hyperlinks to PDF scans of the paper documents were generated for public access to the documents. Assay returns house analytical results obtained from DOGAMIs in-house fire assay, chemical, and spectrograph laboratories between 1937 and 1985. Understand that recreation in or around inactive mine sites is extremely dangerous, and can result in serious injury or death. Stay out and stay alive! The purpose of this MILO-Release 4 is for use as reference material supporting local- to statewide-scale mineral resource and environmental assessments. These data provide a searchable catalogue with links to supporting digital documentation that allows users to extract, research, and display historical mining and mineral resource information. 08/01/1991-08/31/2024 Planned Biennial ISO 19115 Topic Category geoscientificinformation Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus stone metallic mineral industrial mineral mineral resource zeolite sand and gravel USGS Thesaurus geospatial datasets hazards hazard preparedness scientific interpretation time series datasets Custom MILO (Mineral Information Layer for Oregon) Mine Mineral fuel Aggregate Gemstone Borrow Pit Prospect Quarry Gravel Pit Mineral Occurrence Oregon Geospatial Enterprise Office Metadata Keyword Thesaurus United States North America Oregon Baker Benton Clackamas Clatsop Columbia Coos Crook Curry Deschutes Douglas Grant Harney Hood River Jackson Jefferson Josephine Klamath Lake Lane Lincoln Linn Malheur Marion Morrow Multnomah Polk Sherman Tillamook Umatilla Union Wallowa Wasco Washington Wheeler Yamhill None REPORT DATA: This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information. This publication cannot substitute for site-specific investigations by qualified practitioners. Site-specific data may give results that differ from the results shown in the publication. See the accompanying text report for more details on the limitations of the methods and data used to prepare this publication. Oregon Department of Geology and Mineral Industries mailing and physical address
800 NE Oregon Street Suite 965
Portland Oregon 97232 USA 1 971 673 1555 1 971 673 1562 dogami-info@dogami.oregon.gov When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from https://www.oregon.gov/dogami/pages/default.aspx Carlie J.M. Azzopardi Oregon Department of Geology and Mineral Industries This update and release of MILO-4 was supported through a grant from the National Geological and Geophysical Data Preservation Program (NGGDPP) under cooperative agreement number G23AP00218-01 (2023). Additional funds were provided by the State of Oregon. Unclassified Attribute accuracy is tested by manual comparison of the source and hard copy scans but despite the checks there may be some attributes that are still mislabeled. Certain fields like state and county were corrected to match a list of acceptable values. Dates were limited to the between the years 1937 and 1988 representing the time the laboratory was in use. On occasion, some assay records included quantitative data without specified units. In these cases, the units were inferred and recorded based on the magnitude of the number. No duplicated features exist although individual table features may overlap and share the same coordinates but have differences in attribute(s). The data were collected and reported by numerous people, the descriptions provided are not highly consistent in terminology or similar characteristics may be described differently. In an attempt for some consistency some terminology was updated to a single common usage. This table includes Portland and Grants Pass records only. No Baker City records are included in this iteration. These records are intended to be appended to a future MILO update. Most assay records did not include every single field of data; some clients may not have been able to provide this information, were reluctant to do so, or handwriting was illegible. Assay return PDFs run from the implementation of Oregon Revised Statue 516.040 in year 1937 to 1985. The law governing these services entitled any individual or group of two or more persons working together to submit two samples from mines and prospects within the state per month for free laboratory analysis of grade and/or identity. Samples originating from mine occurrences undergoing active development, mining, milling, or where ore was being shipped from the prospect were not allowed. Mining engineers sampling mine occurrences professionally for evaluation purposes were also prohibited from submitting samples. Fire assay and chemical analysis services became restricted starting on January 1, 1981, whereafter analytical facilities at DOGAMI were reserved for in-house research in connection with staff programs and projects. Assay returns run post 1985 were published within project specific publications and not as stand alone documents, therefore are not included in this table. Grants Pass log records the total number of samples assayed between 1937-1985 at 20% higher than those entered into this table. Baker City is likely to hold some of these records that will be added in future updates. Individual Adobe Portable Document Format [PDF] files were created from high-resolution scans of the original fire assay, chemical, and spectrograph Logs and Request for Sample Information paper files. Handwritten information from each assay record was transcribed into a master Microsoft Excel spreadsheet resulting in 15,405 assay table entries. A new feature table called Assay Returns was developed using Esri ArcPRO v. 3.3 from the master Microsoft Excel spreadsheet. Due to the complexities of the parent data this table does not completely conform to the Geologic Map Schema (GeMS), designed by the U.S. Geological Survey. These records were related to geographic locations, in the Assay Point Locations feature class, based on the following hierarchy: 1) Points were associated to the Public Land Survey System (PLSS) shapefile centroid first based on Township, Range, and Section information; 2) Points that did not have corresponding PLSS information were associated to the Oregon counties shapefile centroid; 3) The final parameter for records that did not meet criteria 1 and 2 were assigned to the Oregon shapefile centroid. Oregon Department of Geology and Mineral Industries mailing and physical address
800 NE Oregon Street Suite 965
Portland Oregon 97232 USA 1 971 673 1555 1 971 673 1562 dogami-info@dogami.oregon.gov When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from https://www.oregon.gov/dogami/pages/default.aspx AssayReturns DOGAMIPrime_ID Primary key. First DOGAMI identification number Oregon Department of Geology and Mineral Industries DOGAMISecond_ID second DOGAMI identification number Oregon Department of Geology and Mineral Industries DOGAMIThird_ID third DOGAMI identification number Oregon Department of Geology and Mineral Industries USGSPrime_ID first USGS identification number Oregon Department of Geology and Mineral Industries USGSSecond_ID second USGS identification number Oregon Department of Geology and Mineral Industries Name name of person submitting sample for assay Oregon Department of Geology and Mineral Industries Address address of person submitting sample for assay Oregon Department of Geology and Mineral Industries City city of person submitting sample for assay Oregon Department of Geology and Mineral Industries State state of person submitting sample for assay Oregon Department of Geology and Mineral Industries Zipcode zip code of person submitting sample for assay Oregon Department of Geology and Mineral Industries Date date sample was submitted Oregon Department of Geology and Mineral Industries Mine name of mine sampled Oregon Department of Geology and Mineral Industries Claim name of claim sampled Oregon Department of Geology and Mineral Industries PropertyOwner owner of property where sample was taken Oregon Department of Geology and Mineral Industries County county location Oregon Department of Geology and Mineral Industries District mining district Oregon Department of Geology and Mineral Industries Township township location Oregon Department of Geology and Mineral Industries Range range location Oregon Department of Geology and Mineral Industries Section section location Oregon Department of Geology and Mineral Industries QuarterSection section Oregon Department of Geology and Mineral Industries QuarterQuarterSection section Oregon Department of Geology and Mineral Industries Directions how far from passable road and name of road Oregon Department of Geology and Mineral Industries Type type of sample taken Oregon Department of Geology and Mineral Industries Location where sample was taken from Oregon Department of Geology and Mineral Industries Description description of sample Oregon Department of Geology and Mineral Industries Gravity specific gravity Oregon Department of Geology and Mineral Industries Radioactivity radioactivity Oregon Department of Geology and Mineral Industries Ag_PPB silver, parts per billion Oregon Department of Geology and Mineral Industries Ag_PPM_S silver, parts per million Oregon Department of Geology and Mineral Industries Ag_oz_T silver, ounces per ton Oregon Department of Geology and Mineral Industries Ag_Percent silver, percent Oregon Department of Geology and Mineral Industries Al_Percent aluminum, percent Oregon Department of Geology and Mineral Industries Al2O3_Percent aluminum oxide, alumina, percent Oregon Department of Geology and Mineral Industries As_PPM_S arsenic, parts per million Oregon Department of Geology and Mineral Industries As_Percent arsenic, percent Oregon Department of Geology and Mineral Industries Ash_Percent ash, percent Oregon Department of Geology and Mineral Industries Au_PPB gold, parts per billion Oregon Department of Geology and Mineral Industries Au_PPM_S gold, parts per million Oregon Department of Geology and Mineral Industries Au_oz_T gold, ounces per ton Oregon Department of Geology and Mineral Industries Au_Percent gold, percent Oregon Department of Geology and Mineral Industries B_PPM_S boron, parts per million Oregon Department of Geology and Mineral Industries B_Percent boron, percent Oregon Department of Geology and Mineral Industries Ba_PPM_S barium, parts per million Oregon Department of Geology and Mineral Industries Ba_Percent barium, percent Oregon Department of Geology and Mineral Industries BaO_Percent barium oxide, percent Oregon Department of Geology and Mineral Industries BaSO4_Percent barium sulfate, percent Oregon Department of Geology and Mineral Industries Be_PPM_S beryllium, parts per million Oregon Department of Geology and Mineral Industries Be_Percent beryllium, percent Oregon Department of Geology and Mineral Industries BeO_Percent beryllium oxide, percent Oregon Department of Geology and Mineral Industries Bi_PPM_S bismuth, parts per million Oregon Department of Geology and Mineral Industries Bi_Percent bismuth, percent Oregon Department of Geology and Mineral Industries Bo_Percent borate, percent Oregon Department of Geology and Mineral Industries C_Percent carbon, percent Oregon Department of Geology and Mineral Industries Ca_PPM_S calcium, parts per million Oregon Department of Geology and Mineral Industries Ca_Percent calcium, percent Oregon Department of Geology and Mineral Industries Calcium_Carbonate_Percent calcium carbonate, percent Oregon Department of Geology and Mineral Industries CaO_Percent calcium oxide, lime, percent Oregon Department of Geology and Mineral Industries CaCO3_Percent calcite, calcium carbonate, percent Oregon Department of Geology and Mineral Industries CaF2_Percent calcium fluoride, percent Oregon Department of Geology and Mineral Industries Cb_Percent columbium, percent Oregon Department of Geology and Mineral Industries Cb2O5_Percent columbium oxide, percent Oregon Department of Geology and Mineral Industries Cd_PPM_S cadmium, parts per million Oregon Department of Geology and Mineral Industries Cd_Percent cadmium, percent Oregon Department of Geology and Mineral Industries Ce_Percent cerium, percent Oregon Department of Geology and Mineral Industries Chromite_Percent chromite, percent Oregon Department of Geology and Mineral Industries Co_oz_T cobalt, ounces per ton Oregon Department of Geology and Mineral Industries Co_PPM_S cobalt, parts per million Oregon Department of Geology and Mineral Industries Co_Percent cobalt, percent Oregon Department of Geology and Mineral Industries Cr_PPM_S chromium, parts per million Oregon Department of Geology and Mineral Industries Cr_Percent chromium, percent Oregon Department of Geology and Mineral Industries Cr2O3_Percent chromium oxide, chrome, percent Oregon Department of Geology and Mineral Industries Cs_Percent cesium, percent Oregon Department of Geology and Mineral Industries Cu_oz_T copper, ounces per ton Oregon Department of Geology and Mineral Industries Cu_PPM_S copper, parts per million Oregon Department of Geology and Mineral Industries Cu_Percent copper, percent Oregon Department of Geology and Mineral Industries F_Percent fluorine, percent Oregon Department of Geology and Mineral Industries Fe_PPM_S iron, parts per million Oregon Department of Geology and Mineral Industries Fe_Percent iron, percent Oregon Department of Geology and Mineral Industries FeAlO3_Percent available aluminum and iron oxides, percent Oregon Department of Geology and Mineral Industries FeO_Percent wstite (iron (II) oxide), percent Oregon Department of Geology and Mineral Industries Fe2O3_Percent ferric oxide red, percent Oregon Department of Geology and Mineral Industries Ga_PPM_S gallium, parts per million Oregon Department of Geology and Mineral Industries Ga_Percent gallium, percent Oregon Department of Geology and Mineral Industries Ge_Percent germanium, percent Oregon Department of Geology and Mineral Industries H_Ions hydrogen ion Oregon Department of Geology and Mineral Industries Hf_Percent hafnium, percent Oregon Department of Geology and Mineral Industries Hg_Percent mercury, percent Oregon Department of Geology and Mineral Industries Hg_cc_Per_Half_gm mercury, cubic centimeter per gram Oregon Department of Geology and Mineral Industries Hg_oz_T mercury, ounces per ton Oregon Department of Geology and Mineral Industries Hg_lb_T mercury, pounds per ton Oregon Department of Geology and Mineral Industries Hg_PPM_S mercury, parts per million Oregon Department of Geology and Mineral Industries In_Percent indium, percent Oregon Department of Geology and Mineral Industries Ir_Percent iridium, percent Oregon Department of Geology and Mineral Industries K_Percent potassium, percent Oregon Department of Geology and Mineral Industries K2O_Percent potassium oxide, percent Oregon Department of Geology and Mineral Industries La_PPM_S lanthanum, parts per million Oregon Department of Geology and Mineral Industries La_Percent lanthanum, percent Oregon Department of Geology and Mineral Industries Li_Percent lithium, percent Oregon Department of Geology and Mineral Industries Mg_PPM_S magnesium, parts per million Oregon Department of Geology and Mineral Industries Mg_Percent magnesium, percent Oregon Department of Geology and Mineral Industries MgCO3_Percent magnesium carbonate, percent Oregon Department of Geology and Mineral Industries MgO_Percent magnesium oxide, magnesia, percent Oregon Department of Geology and Mineral Industries MgO_gmsPer1000cc magnesium oxide, magnesia, grams per 1000cc Oregon Department of Geology and Mineral Industries Mn_PPM_S manganese, parts per million Oregon Department of Geology and Mineral Industries Mn_Percent manganese, percent Oregon Department of Geology and Mineral Industries MnO2_Percent manganese dioxide, percent Oregon Department of Geology and Mineral Industries Mo_oz_T molybdenum, ounces per ton Oregon Department of Geology and Mineral Industries Mo_PPM_S molybdenum, parts per million Oregon Department of Geology and Mineral Industries Mo_Percent molybdenum, percent Oregon Department of Geology and Mineral Industries Na_Percent sodium, percent Oregon Department of Geology and Mineral Industries Na2O_Percent sodium oxide, percent Oregon Department of Geology and Mineral Industries Nb_PPM_S niobium, parts per million Oregon Department of Geology and Mineral Industries Nb_Percent niobium, percent Oregon Department of Geology and Mineral Industries Nd_Percent neodymium, percent Oregon Department of Geology and Mineral Industries Ni_oz_T nickel, ounces per ton Oregon Department of Geology and Mineral Industries Ni_PPM_S nickel, parts per million Oregon Department of Geology and Mineral Industries Ni_Percent nickel, percent Oregon Department of Geology and Mineral Industries Os_Percent osmium, percent Oregon Department of Geology and Mineral Industries P_PPM_S phosphorus, parts per million Oregon Department of Geology and Mineral Industries P_Percent phosphorus, percent Oregon Department of Geology and Mineral Industries PO4_Percent phosphate , percent Oregon Department of Geology and Mineral Industries P2O5_Percent phosphorus oxide, percent Oregon Department of Geology and Mineral Industries Pb_oz_T lead, ounces per ton Oregon Department of Geology and Mineral Industries Pb_PPM_S lead, parts per million Oregon Department of Geology and Mineral Industries Pb_Percent lead, percent Oregon Department of Geology and Mineral Industries Pd_Percent palladium, percent Oregon Department of Geology and Mineral Industries Pd_oz_T palladium, ounces per ton Oregon Department of Geology and Mineral Industries Pr_Percent praseodymium, percent Oregon Department of Geology and Mineral Industries Pt_Percent platinum, percent Oregon Department of Geology and Mineral Industries Pt_oz_T platinum, ounces per ton Oregon Department of Geology and Mineral Industries Ra_Percent radium, percent Oregon Department of Geology and Mineral Industries Rh_Percent rhodium, percent Oregon Department of Geology and Mineral Industries Rh_And_Pt_oz_T rhodium and platinum, ounces per ton Oregon Department of Geology and Mineral Industries Ru_Percent ruthenium, percent Oregon Department of Geology and Mineral Industries S_Percent sulfur, percent Oregon Department of Geology and Mineral Industries SO3_Percent sulfite , percent Oregon Department of Geology and Mineral Industries SO4_Percent sulfate, percent Oregon Department of Geology and Mineral Industries Sb_PPM_S antimony, parts per million Oregon Department of Geology and Mineral Industries Sb_Percent antimony, percent Oregon Department of Geology and Mineral Industries Sc_PPM_S scandium, parts per million Oregon Department of Geology and Mineral Industries Se_PPM_S selenium, parts per million Oregon Department of Geology and Mineral Industries Se_Percent selenium, percent Oregon Department of Geology and Mineral Industries Si_Percent silicon, percent Oregon Department of Geology and Mineral Industries SiO2_Percent silica, percent Oregon Department of Geology and Mineral Industries SiO2_InsolublePercent silica insoluble, percent Oregon Department of Geology and Mineral Industries Sn_PPM_S tin, parts per million Oregon Department of Geology and Mineral Industries Sn_Percent tin, percent Oregon Department of Geology and Mineral Industries Sr_PPM_S strontium, parts per million Oregon Department of Geology and Mineral Industries Sr_Percent strontium, percent Oregon Department of Geology and Mineral Industries Stibnite_Percent stibnite, percent Oregon Department of Geology and Mineral Industries Ta_Percent tantalum, percent Oregon Department of Geology and Mineral Industries Ta2O5_Percent tantalum oxide, percent Oregon Department of Geology and Mineral Industries Tb_Percent terbium, percent Oregon Department of Geology and Mineral Industries Te_Percent tellurium, percent Oregon Department of Geology and Mineral Industries Th_PPM_S thorium, parts per million Oregon Department of Geology and Mineral Industries Th_Percent thorium, percent Oregon Department of Geology and Mineral Industries Ti_PPM_S titanium, parts per million Oregon Department of Geology and Mineral Industries Ti_Percent titanium, percent Oregon Department of Geology and Mineral Industries TiO2_Percent titanium oxide, percent Oregon Department of Geology and Mineral Industries Tl_PPM_S thallium, parts per million Oregon Department of Geology and Mineral Industries Tl_Percent thallium, percent Oregon Department of Geology and Mineral Industries U_PPM_S uranium, parts per million Oregon Department of Geology and Mineral Industries U_Percent uranium, percent Oregon Department of Geology and Mineral Industries eU_Percent uranium equivalent, percent Oregon Department of Geology and Mineral Industries U3O8_Percent uranium oxide, percent Oregon Department of Geology and Mineral Industries V_PPM_S vanadium, parts per million Oregon Department of Geology and Mineral Industries V_Percent vanadium, percent Oregon Department of Geology and Mineral Industries V2O3_Percent vanadium trioxide, percent Oregon Department of Geology and Mineral Industries W_PPM_S tungsten, parts per million Oregon Department of Geology and Mineral Industries W_Percent tungsten, percent Oregon Department of Geology and Mineral Industries WO3_Percent tungsten oxide, percent Oregon Department of Geology and Mineral Industries Y_PPM_S yttrium, parts per million Oregon Department of Geology and Mineral Industries Y_Percent yttrium, percent Oregon Department of Geology and Mineral Industries Yb_Percent ytterbium, percent Oregon Department of Geology and Mineral Industries Zn_oz_T zinc, ounces per ton Oregon Department of Geology and Mineral Industries Zn_PPM_S zinc, parts per million Oregon Department of Geology and Mineral Industries Zn_Percent zinc, percent Oregon Department of Geology and Mineral Industries Zr_PPM_S zirconium, parts per million Oregon Department of Geology and Mineral Industries Zr_Percent zirconium, percent Oregon Department of Geology and Mineral Industries ZrO2_Percent zirconia oxide, percent Oregon Department of Geology and Mineral Industries RareEarths rare earths Oregon Department of Geology and Mineral Industries Petroleum_Percent petroleum, percent Oregon Department of Geology and Mineral Industries Water_Percent water, percent Oregon Department of Geology and Mineral Industries Others_Percent others, percent Oregon Department of Geology and Mineral Industries Solids_gmsPer1000cc solids, grams per 1000cc Oregon Department of Geology and Mineral Industries SolubleAlkalis_Percent soluble alkalis, percent Oregon Department of Geology and Mineral Industries Soluble_Fe_Percent soluble iron, percent Oregon Department of Geology and Mineral Industries SolubleMatter_Percent soluble matter, percent Oregon Department of Geology and Mineral Industries Insoluble_Percent insoluble residue, percent Oregon Department of Geology and Mineral Industries InsolubleAcid_Percent insoluble residue mixed with acid, percent Oregon Department of Geology and Mineral Industries InsolubleWater_Percent insoluble residue mixed with water, percent Oregon Department of Geology and Mineral Industries Insoluble_Hg_PPM insoluble residue mixed with mercury, parts per million Oregon Department of Geology and Mineral Industries Moisture_Percent moisture, percent Oregon Department of Geology and Mineral Industries MoistureAndIgnitionLoss_Percent moisture and ignition loss, percent Oregon Department of Geology and Mineral Industries LossOnIgnition_Percent loss on ignition, percent Oregon Department of Geology and Mineral Industries Notes additional information on record Oregon Department of Geology and Mineral Industries Hyperlink PLSS_ID Foreign key. Values are listed as Township Range Section Quarter Quarter as available otherwise County or State. Example: T37S R09W 09 SENW Oregon Department of Geology and Mineral Industries This table contains fields for client information (e.g., name, address, citizenship), sample location information (e.g., county, mining district, township, range, section, and the analysis desired), and sample type (e.g., channel, grab, description; nature of sample or mineralization), which were provided by the client at the time of submittal to DOGAMI. Hyperlinks to PDF scans of the paper documents were generated for public access to the documents. Assay returns house analytical results obtained from DOGAMIs in-house fire assay, chemical, and spectrograph laboratories between 1937 and 1985. Oregon Department of Geology and Mineral Industries mailing and physical address
800 NE Oregon Street Suite 965
Portland Oregon 97232 USA 1 971 673 1555 1 971 673 1562 dogami-info@dogami.oregon.gov When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from https://www.oregon.gov/dogami/pages/default.aspx Although these data have been processed successfully on a computer system at the Oregon Department of Geology and Mineral Industries, no warranty expressed or implied is made by DOGAMI regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. "GDB" Esri File Geodatabase 08/01/1991-08/31/2024 2024-08-31 00:00:00 Oregon Department of Geology and Mineral Industries mailing and physical address
800 NE Oregon Street Suite 965
Portland Oregon 97232 USA 1 971 673 1555 1 971 673 1562 dogami-info@dogami.oregon.gov When contacting DOGAMI about this data set, please reference the data set title or other identifying information in your correspondence. DOGAMI publications can be downloaded from https://www.oregon.gov/dogami/pages/default.aspx Oregon Department of Geology and Mineral Industries Metadata Standard 1.4 None None None None None