Exploratory Borings

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

2025

Exploration drilling in 2025

• Download map of exploration drill hole locations completed in 2025

Table: Exploration Drilling in 2025

Exploration Company	Number of Drill Holes	Target Commodity	Counties
Talon Nickel (USA) LLC	25	Ni, Cu	Aitkin
NewRange Copper Nickel LLC	6	Cu, Ni	St. Louis
^United States Steel Co. - Minntac	13	Iron	St. Louis
Pulsar Helium Inc	3	He	Lake
Total	47

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.

2024

Exploration drilling in 2024

• Download map of exploration drill hole locations completed in 2024

Table: Exploration Drilling in 2024

Exploration Company	Number of Drill Holes	Target Commodity	Counties
Talon Nickel (USA) LLC	57	Ni, Cu	Aitkin
NewRange Copper Nickel LLC	32	Cu, Ni, PGM, Co	St. Louis
^United States Steel Co. - Minntac	11	Iron	St, Louis
Pulsar Helium Inc	1	He	Lake
Kennecott Exploration Company	1	Ni, Cu	Carlton
^Mesabi Metallics Company LLC	18	Iron	Itasca
Franconia Minerals	11	Cu, Ni, PGM	St. Louis
Total	131

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.

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)

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

Click to enlarge