Exploratory Borings

Diamond drill core bit

Drill core (cut in half) inside diamond drill core bit

Annual Data and Maps

The Lands and Minerals Division compiles data related to private exploratory borings, or drill holes, in Minnesota. Provided here are data and maps pertaining to exploratory borings in Minnesota since 1987.

If you have questions please contact:
Minnesota Department of Natural Resources
tel. 651-296-6157
tel. 888-646-6367
 

Did you know?

  • Mineral exploration drill holes make up less than 1% of all drilling in the state.
    View slide »
  • Drill holes are sealed according to state law.
    Visit Department of Health to learn more »
  • It costs an estimated $100,000 to drill 1,000 feet of drill core ($100 per/ft). This is an estimate and includes costs such as: geologist, site selection, geophysics, salaries, and drilling costs. 
  • Only 2.6% of all state leased parcels had exploration drilling completed on them according to an analysis of exploration drilling on state metallic minerals leases over 50 years.
    View analysis »
  • The average size of a drill pad is 70'x70' which is approximately 1/10 of an acre in extent. At this size it would take 400 exploratory drill pad sites to fill a 40 acre footprint.

Learn more

Mineral Exploration Process »
Mineral Exploration Regulations »
State Oversight of Metallic Mineral Exploration Activities »

Exploration by Year

2023

Exploration drilling in 2023

  • Download map of exploration drill hole locations completed in 2023

Table: Exploration Drilling in 2023

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Talon Nickel (USA) LLC 60 Nickel Aitkin
Teck American Inc. 15 Cu+Ni+PGM+Co St. Louis
NewRange Copper Nickel LLC 18 Cu, Ni St, Louis
North Star Manganese 32 Mn Crow Wing
^Hibbing Taconite Co. 2 Iron St. Louis
^Cleveland Cliffs MN Land Development Co. 39 Iron St. Louis
^United States Steel Co. - Minntac 8 Iron St. Louis
Total 174    
Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM+Co indicates Copper, Nickel, Platinum Group Metals, and Cobalt.
^Iron exploration when it is done outside of a mining area described in a permit to mine.
2022

Exploration drilling in 2022

  • Download map of exploration drill hole locations completed in 2022

Table: Exploration Drilling in 2022

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Talon Nickel (USA) LLC 68 Nickel Aitkin
Teck American Inc. 10 Cu+Ni+PGM+Co St. Louis
Vermilion Gold LLC 18 Gold Itasca, St. Louis
^Arcelor Mittal Minorca Mine Inc. 9 Iron St. Louis
^Glacier Park Iron Ore 3 Iron St. Louis
^United States Steel Co. - Minntac 16 Iron St. Louis
Total 124    
Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM+Co indicates Copper, Nickel, Platinum Group Metals, and Cobalt.
^Iron exploration when it is done outside of a mining area described in a permit to mine.
2021

Exploration drilling in 2021

  • Download map of exploration drill hole locations completed in 2021

Table: Exploration Drilling in 2021

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Talon Nickel (USA) LLC 108 Nickel Aitkin
Teck American Inc. 6 Cu+Ni+PGM+Co St. Louis
Vermilion Gold LLC 29 Gold Itasca, St. Louis
^Cleveland Cliffs MN Land Development Co. 1 Iron St. Louis
^Hibbing Taconite Co. 2 Iron St. Louis
Total 146    
Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM+Co indicates Copper, Nickel, Platinum Group Metals, and Cobalt.
^Iron exploration when it is done outside of a mining area described in a permit to mine.
2020

Exploration drilling in 2020

  • Download map of exploration drill hole locations completed in 2020

Table: Exploration Drilling in 2020

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Encampment Minerals, Inc. 2 Cu+Ni+PGM St. Louis
Talon Nickel (USA) LLC 19** Nickel Aitkin
^Arcelor Mittal Minorca Mine Inc. 4 Iron St. Louis
Total 25    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals
**Count includes seven wedged holes, also known as daughter holes, child holes, branch holes, or wedges. A wedged hole is drilled when the drill bit is purposely deflected out the side of a parent (existing) hole.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2019

Exploration drilling in 2019

  • Download map of exploration drill hole locations completed in 2019

Table: Exploration Drilling in 2019

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
AngloGold Ashanti Minnesota 55 Gold Itasca and St. Louis
Encampment Minerals, Inc. 2 Cu+Ni+PGM St. Louis
Vermillion Gold 6 Gold Itasca
^Hibbing Taconite Company/Cleveland Cliffs 4 Iron St. Louis
Total 67    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2018

Exploration drilling in 2018

  • Download map of exploration drill hole locations completed in 2018

Table: Exploration Drilling in 2018

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
AngloGold Ashanti Minnesota 99 Gold Itasca and St. Louis
Kennecott Exploration Co. 4** Cu+Ni Aitkin
Polymet Mining Inc. 18 Cu+Ni+PGM St. Louis
^ArcelorMittal Minorca Mine Inc. 26 Iron St. Louis
^Cleveland Cliffs Minnesota Land Development LLC 6 Iron Itasca
^Hibbing Taconite Company/Cleveland Cliffs 3 Iron St. Louis
Total 156    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals
**Count includes three wedged holes, also known as daughter holes, child holes, branch holes, or wedges. A wedged hole is drilled when the drill bit is purposely deflected out the side of a parent (existing) hole.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2017

Exploration drilling in 2017

  • Download map of exploration drill hole locations completed in 2017

Table: Exploration Drilling in 2017

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
AngloGold Ashanti Minnesota 29 Gold Koochiching
Kennecott Exploration Co. 12 Cu+Ni+PGM Aitkin
Vermillion Gold LLC 14 Gold St. Louis
Total 55    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals

2016

Exploration drilling in 2016

  • Download map of exploration drill hole locations completed in 2016

Table: Exploration Drilling in 2016

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Twin Metals Minnesota LLC 1 Cu+Ni+PGM Lake
Kennecott Exploration Co. 30** Ni+Cu Aitkin
Total 31    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
**Count includes eight wedged holes, also known as daughter holes, child holes, branch holes, or wedges, and one extension. A wedged hole is drilled when the drill bit is purposely deflected out the side of a parent (existing) hole.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2015

Exploration drilling in 2015

  • Download map of exploration drill hole locations completed in 2015
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

The map and table do not show 8 drill holes completed for iron ore in the biwabik iron formation.

Table: Exploration Drilling in 2015

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Encampment Minerals, Inc. 9 Cu+Ni+PGM St. Louis and Lake
Kennecott Exploration Co. 17 Cu+Ni Aitkin and Carlton
Vermillion Gold LLC 7 Gold St. Louis
^ArcelorMittal 8 Iron Itasca
Total 41    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2014

Exploration drilling in 2014

  • Download map of exploration drill hole locations completed in 2014
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

The map and table do not show 40 drill holes completed for iron ore in the biwabik iron formation and 17 drill holes completed by MnDOT for highway projects.

Table: Exploration Drilling in 2014

Exploration Company or Agency Number of
Drill Holes		 Target
Commodity		 Counties
DMC USA LLC 5 Cu+Ni+PGM St. Louis and Lake
Kennecott Exploration Co. 12 Cu+Ni Aitkin
Twin Metals Minnesota 9 Cu+Ni+PGM Lake
^Hibbing Taconite Co. 17 Iron St. Louis
^Mag Mining LLC 12 Iron Itasca
^US Steel Corp. 11 Iron Itasca
MnDOT 17 Iron - Condemnation drilling; highway 53 relocation St. Louis
Total 83    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2013

Exploration drilling in 2013

  • Download map of exploration drill hole locations completed in 2013
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

The map and table do not show 10 drill holes drilled by US Steel for iron ore in the biwabik iron formation.

Table: Exploration Drilling in 2013

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
DMC USA LLC 24 Cu+Ni+PGM Lake
Encampment Minerals 1 Cu+Ni+PGM St. Louis
Kennecott Exploration Co. 39** Cu+Ni+PGM Aitkin
Minerals Processing Corp. 4 Cu+Ni+PGM Aitkin
Teck American Inc. 72 Cu+Ni+PGM St. Louis
Twin Metals Minnesota 104*** Cu+Ni+PGM St. Louis and Lake
^US Steel 10 Iron St. Louis
Total 254    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
**Count includes one wedged hole, also known as daughter holes, child holes, branch holes, or wedges. A wedged hole is drilled when the drill bit is purposely deflected out the side of a parent (existing) hole.
***Count includes five wedged holes.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2012

Exploration drilling in 2012

  • Download map of exploration drill hole locations completed in 2012
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

The map and table do not show 11 drill holes drilled by Hibbing Taconite and 1 drill hole drilled by ArcelorMittal in 2012.

Table: Exploration Drilling in 2012

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Cooperative Minerals Resources 4 Manganese Crow Wing
DMC USA LLC 27 Cu+Ni+PGM Lake
Encampment Minerals 5 Cu+Ni+PGM St. Louis
HTX Minerals 1 Cu+Ni+PGM Aitkin
Kennecott Exploration Co. 29 Cu+Ni+PGM Aitkin
Twin Metals Minnesota 131 Cu+Ni+PGM St. Louis and Lake
^Hibbing Taconite 11 Iron St. Louis
^ArcelorMittal 1 Iron St. Louis
Total 209    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2011

Exploration drilling in 2011

  • Download map of exploration drill hole locations completed in 2011
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

The map and table do not show 10 drill holes drilled by United States Steel in 2011.

Table: Exploration Drilling in 2011

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
Cardero Resources 11 Iron and Titanium St. Louis
Cooperative Mineral Resources 4 Manganese Crow Wing
Duluth Metals 8 Cu+Ni+PGM Lake
Encampment Minerals 7 Cu+Ni+PGM St. Louis
Kennecott Exploration Co. 6 Cu+Ni+PGM Aitkin and Carlton
MMG USA 2 Cu+Ni+PGM Brown and Blue Earth
Prime Meridian Resources 3 Cu+Ni+PGM Koochiching
Twin Metals Minnesota 133 Cu+Ni+PGM St. Louis and Lake
^United States Steel 10 Iron St. Louis
Western Metals 4 Cu+Ni+PGM Lyon and Renville
Total 188    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

2005-2010

Exploration drilling between 2005-2010

  • Download map of exploration drill hole locations between 2005-2010.
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

Table: Exploration Drilling 2005-2010

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
ACME-OCHS Brick and Stone 19 Kaolin Clay Brown, Redwood, and Renville
Cardero Resources 36 Iron and Titanium St. Louis
Duluth Metals/Twin Metals 205 Cu+Ni+PGM Lake
Encampment Minerals 37 Cu+Ni+PGM Lake and St. Louis
Franconia Minerals 50 Cu+Ni+PGM Lake and St. Louis
Kennecott Exploration Co. 124 Cu+Ni+PGM, Zinc, Lead Aitkin, Carlton, Kanabec, Mille Lacs, Morrison, and Stearns
Lehmann Exploration 14 Gold Itasca and St. Louis
^Mesabi Nugget 3 Iron St. Louis
Minerals Processing Corp. 11 Cu+Ni+PGM, Zinc, Lead Aitkin and Carlton
PolyMet Mining Corp. 234 Cu+Ni+PGM St. Louis
Teck American Inc. 137 Cu+Ni+PGM St. Louis
^United States Steel Corp. 49 Iron Itasca and St. Louis
Western Metals LLC 5 Cu+Ni+PGM Lyon
WMC 5 Cu+Ni+PGM Renville and Yellow Medicine
Total 929    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.
^Iron exploration when it is done outside of a mining area described in a permit to mine.

Table: Exploration Drilling 2005-2010 By Year

Exploration Company 2005 2006 2007 2008 2009 2010 Total
ACME-OCHS Brick and Stone       16 3   19
Cardero Resources           36 36
Duluth Metals/Twin Metals   10 72 72 2 49 205
Encampment Minerals       24 13   37
Franconia Minerals 4 7 16 12   11 50
Kennecott Exploration Co. 19   15 52 17 21 124
Lehmann Exploration         4 10 14
^Mesabi Nugget       3     3
Minerals Processing Corp.             11
PolyMet Mining Corp. 107   61     66 234
Teck American Inc.     22 115     137
^United States Steel Corp.     8 28 7 6 49
Western Metals LLC           5 5
WMC 5           5
Total 135 17 194 322 46 215 929
1999-2004

Exploration drilling between 1999-2004

  • Download map of exploration drill hole locations completed between 1999-2004
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

Table: Exploration Drilling 1999-2004

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
BHP Minerals International Inc. 3 Iron St. Louis
Encampment Minerals 6 Cu+Ni+PGM Lake
Kennecott Exploration Co. 25 Cu+Ni+PGM, Zinc, Lead Aitkin, Carlton, Morrison, and Stearns
Lehmann Exploration 28 Cu+Ni+PGM Lake and St. Louis
Rendrag Inc. 1 Cu+Ni+PGM St. Louis
Wallbridge America LTD 3 Cu+Ni+PGM Lake
WMC 1 Cu+Ni+PGM Renville
Total 67    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.

Table: Exploration Drilling 1999-2004 By Year

Exploration Company 1999 2000 2001 2002 2003 2004 Total
BHP Minerals International Inc. 2 1         3
Encampment Minerals           6 6
Kennecott Exploration Co.       3 11 11 25
Lehmann Exploration 2 12 7 6 1   28
Rendrag Inc. 1           1
Wallbridge America LTD 1 1 1       3
WMC 5         1 1
Total 6 14 8 9 12 18 67
1993-1998

Exploration drilling between 1993-1998

  • Download map of exploration drill hole locations completed between 1993-1998
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

Table: Exploration Drilling 1993-1998

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
American Shield 5 Cu+Ni+PGM St. Louis
Cominco 16 Cu+Ni+PGM, Zinc, Lead Aitkin, Carlton, Lake of the Woods, St. Louis, and Wilkin
Exmin Corporation 8 Diamond Beltrami, Koochiching, Marshall, and Roseau
Great Lakes Exploration 1 Cu+Ni+PGM Carlton
Lehmann 2 Cu+Ni+PGM St. Louis
Phelps Dodge 3 Cu+Ni+PGM Roseau
Total 35    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals

Table: Exploration Drilling 1993-1998 By Year

Exploration Company 1993 1994 1995 1996 1997 1998 Total
American Shield   4     1   5
Cominco   1 9 5   1 16
Exmin Corporation 2   1   5   8
Great Lakes Exploration 1           1
Lehmann     1     1 2
Phelps Dodge 3           3
Total 6 5 11 5 6 2 35
1987-1992

Exploration drilling between 1987-1992

  • Download map of exploration drill hole locations completed between 1993-1998
  • Associated table with drill hole information; County, Township, Range, Section, Company, Drill Hole Name, Depth (if known), and Date Drilled.
  • Additional information for individual boreholes can be found using DNR's Drill Core Library web map.

Table: Exploration Drilling 1987-1992

Exploration Company Number of
Drill Holes		 Target
Commodity		 Counties
American Shield 1 Cu+Ni+PGM St. Louis
Bear Creek 1 Cu+Ni+PGM St. Louis
BHP Minerals International Inc. 5 Gold Koochiching and St. Louis
Coca Mines 19 Gold St. Louis
Cominco 1 Base Metals Norman
Exmin Corporation 30 Diamond Beltrami, Benton, Chippewa, Clay, Clearwater, Koochiching, Lac Qui Parle, Marshall, Mille Lacs, Morrison, Redwood, Renville, St. Louis, Stearns, Stevens, and Wilkin
Exxon 2 Cu+Ni+PGM Roseau and Beltrami
FMC 2 Gold St. Louis
Great Lakes Exploration 5 Cu+Ni+PGM, Zinc, Lead Carlton
Hibbing Taconite Land Co. 31 Iron St. Louis
INCO 12 Cu+Ni+PGM St. Louis
Kennecott Exploration 1 Cu+Ni+PGM St. Louis
Kerr-McGee Corp. 8 Gold Koochiching and St. Louis
Lehmann 14 Cu+Ni+PGM and Gold Itasca (Gold), Lake, and St. Louis
Meridian L&M Co. 18 Gold Itasca
Newmont Exploration Ltd. 134 Gold Beltrami, Itasca, Koochiching, Marshall, Norman, Roseau, and St. Louis
Noranda Exploration 27 Gold Beltrami, Itasca, Norman, and St. Louis
Normin Mining Co. 27 Cu+Ni+PGM Itasca and Koochiching
Phelps Dodge 2 Cu+Ni+PGM Lake of the Woods
Resource Exploration 10 Cu+Ni+PGM St. Louis
Rhude and Fryberger Inc. 11 Gold St. Louis
Total 361    

Notes
The Target Commodity is an interpretation for this summary table.
Cu+Ni+PGM indicates Copper, Nickel, and Platinum Group Metals.

Table: Exploration Drilling 1987-1992 By Year

Exploration Company 1987 1988 1989 1990 1991 1992 Total
American Shield         1   1
Bear Creek   1         1
BHP Minerals International Inc.   1 3 1     5
Coca Mines   19         19
Cominco         1   1
Exmin Corporation 4 7 4 11 4   30
Exxon 1 1         2
FMC     2       2
Great Lakes Exploration   5         5
Hibbing Taconite Land Co.         31   31
INCO     12       12
Kennecott Exploration       1     1
Kerr-McGee Corp.   6 2       8
Lehmann 5 2 3 4     14
Meridian L&M Co. 12 6         18
Newmont Exploration Ltd. 9 19 20 9 72 5 134
Noranda Exploration 3 5 1 10 8   27
Normin Mining Co. 4 6 16 1     27
Phelps Dodge           2 2
Resource Exploration   6   4     10
Rhude and Fryberger Inc. 7   4       11
Total 45 84 67 41 117 7 361

1987-2023 Chart

Number of private exploratory borings, or drill holes, drilled in Minnesota (1987-2023)

Drilling 1987-2023

Chart displaying number of exploration drill holes per year (1987-2023).

Click to enlarge

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