Grindstone Reservoir

Pine County

Near Hinckley

DOW: 58012100

PumpkinseedExcellent · 76Rock BassGood · 55Black CrappiePoor · 16

A 27-acre lake near Hinckley in Pine County — best known for panfish. Last surveyed 1992.

Fish Species (10)

Pumpkinseed

Excellent · 76

Above-normal numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.04 lbs

Catch rate: 3.0 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	3.00	-	0.04 lbs	Standard trap nets
May 1, 1989	0.67	-	-	Standard trap nets

Rock Bass

Good · 55

Typical numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.17 lbs

Catch rate: 0.5 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	0.50	-	0.17 lbs	Standard trap nets
May 1, 1989	1.17	-	-	Standard trap nets

Black Crappie

Poor · 16

Below-normal numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.40 lbs

Catch rate: 0.33 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	0.33	-	0.40 lbs	Standard trap nets
May 1, 1989	2.50	-	-	Standard trap nets

Bluegill

Poor · 12

Below-normal numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.10 lbs

Catch rate: 2.2 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	2.17	-	0.10 lbs	Standard trap nets
May 1, 1989	1.33	-	-	Standard trap nets

Northern Pike

Insufficient

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.65 lbs

Catch rate: 0.67 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	0.67	-	0.65 lbs	Standard trap nets
May 1, 1989	2.83	-	-	Standard trap nets

Other species in this lake (5)

Rough fish, bullheads, and baitfish recorded in DNR surveys — present in the lake, but not typical angling targets.

Black Bullhead

Excellent · 88

Above-normal numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.10 lbs

Catch rate: 1.5 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	1.50	-	0.10 lbs	Standard trap nets
May 1, 1989	71.83	-	-	Standard trap nets

Yellow Bullhead

Good · 54

Typical numbers

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.37 lbs

Catch rate: 1.2 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	1.17	-	0.37 lbs	Standard trap nets
May 1, 1989	1.67	-	-	Standard trap nets

Shorthead Redhorse

Insufficient

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

0.10 lbs

Catch rate: 0.17 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	0.17	-	0.10 lbs	Standard trap nets
May 1, 1989	0.33	-	-	Standard trap nets

Common Carp

Insufficient

Trap-net survey · surveyed May 1989

Last surveyed 1989 — treat with caution

Catch rate: 0.17 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 1, 1989	0.17	-	-	Standard trap nets

White Sucker

Insufficient

Trap-net survey · surveyed May 1992

Last surveyed 1992 — treat with caution

Avg Weight

1.20 lbs

Catch rate: 0.17 per trap net

Survey History

Date	Catch Rate	Avg Length	Avg Weight	Gear
May 28, 1992	0.17	-	1.20 lbs	Standard trap nets
May 1, 1989	0.17	-	-	Standard trap nets

See the best pumpkinseed lakes in Minnesota

Fishing Regulations

Statewide limits

Standard statewide Minnesota limits for the species in this lake.

Northern Pike

Season: May 9, 2026 – Feb 28, 2027

North-central zone

Angling: 10 (not more than 2 over 26". All from 22-26" must be immediatley released).

Crappie

10 combined total

Sunfish

20 combined total

More statewide rules (spearing, rough fish)

Northern Pike

Season: Nov 15, 2026 – Feb 28, 2027

North-central zone

Darkhouse spearing: 10 (only 1 between 22-26" and 1 over 26"; or, only 2 over 26").

Rock Bass

Bowfin, buffalo, carp, carpsuckers, freshwater drum, goldeneye, redhorse, and suckers

no limit

Bullhead

100

Biologist Notes

May 28, 1992On May 28-29, 1992, a brief population assessment was conducted on the Grindstone Reservoir located in the city of Hinckley. Six 3/4 inch trapnets wer…

On May 28-29, 1992, a brief population assessment was conducted on the Grindstone Reservoir located in the city of Hinckley. Six 3/4 inch trapnets were used to evaluate the present fish population status. Annual assessments are used to determine fish abundance so management plans can be implemented. Annual stocking of northern pike, bluegill, and black crappie is provided primarily based on the presence of the fishing pier located on the reservoir. The 1992 net catch found ten species present. The bluegill and black crappie net catches were low. All other species captured by trapnets were similar to previous survey catches. Historical net catches indicate low presence of all species. Factors influencing low numbers by limited to lack of habitat, low dissolved oxygen during winter months, migration up or down stream of the reservoir.

May 1, 1989On May 1-2, 1989, a brief population assessment was conducted on the Grindstone River Reservoir located in the city of Hinckley. Six 3/4 inch trapnets…

On May 1-2, 1989, a brief population assessment was conducted on the Grindstone River Reservoir located in the city of Hinckley. Six 3/4 inch trapnets were set as part of an annual evaluation requested by Richard L. Trombley, Area Fisheries Supervisor. At that time, there were no indications of the potential occurrence of a winter-kill. Eleven fish species were recorded in the trapnet catches which had represented various year-classes. Management plans call for annual stocking of northern pike, bluegill sunfish, and black crappie until a determination of stocking quotas is reevaluated.

Frequently Asked Questions

What fish can you catch in Grindstone Reservoir?

Based on Minnesota DNR survey data, anglers target Pumpkinseed, Rock Bass, Black Crappie, and Bluegill in Grindstone Reservoir. See the full species list above for catch rates, size structure, and quality scores.

Is there public access at Grindstone Reservoir?

We don't have a confirmed public access point on record for Grindstone Reservoir. Check the DNR LakeFinder page for current access details before you go.

How deep is Grindstone Reservoir?

Grindstone Reservoir has a maximum depth of 11 feet, per Minnesota DNR data.

When were the main sport fish in Grindstone Reservoir last surveyed?

The most recent Minnesota DNR survey data for the main sport fish in Grindstone Reservoir is from 1992. Surveys this old should be treated with some caution — fish populations change over time.

Does Grindstone Reservoir have any invasive species?

No invasive species are on record for Grindstone Reservoir in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.

Are there special fishing regulations on Grindstone Reservoir?

No — Grindstone Reservoir has no lake-specific regulations in the 2026 Minnesota DNR regulations, so statewide Minnesota limits apply. The statewide sunfish limit is: 20 combined total. Verify current rules with the Minnesota DNR before keeping fish.