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LakeQuality

Little Gabbro Lake

NR
Not yet rated
6.5 ft clear · Eutrophic · 148 acres
Limited DataEutrophic

Little Gabbro Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.5 ft visibility. Maximum depth: 26 ft. Surface area: 147.54 acres.

Clarity
6.5 ft
Typical in July
70°F
Max depth
26 ft
Area
148 acres
Public access
Yes

Next lake in Lake County

AAugust Lake4.7 ft clear · Lake CountyView →
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Why Little Gabbro Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Little Gabbro Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Little Gabbro Lake is a 148-acre lake in Lake County, Minnesota with a maximum depth of 26 feet. The lake supports 7 documented fish species including black crappie, northern pike, and rock bass. Public access is available.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-06-13. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Ely

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Water quality measurements for Little Gabbro Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Murky, only visible to about 6.5 ft. Trophic State Index: 50.

MetricValueGrade
Water Clarity (Secchi Depth)6.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)50Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Little Gabbro Lake

Compare lakeside cabins, hotels, and vacation rentals near Little Gabbro Lake in Lake County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Little Gabbro Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Little Gabbro Lake typically sits around 70°F at the surface in July. Summer average is about 67°F. Usually warmest in Jul (about 70°F) and coldest in Oct (about 45°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
61°
Jun
64°
Jul
70°
Aug
Sep
Oct
45°
Nov
Dec

Typical surface water temperature by month, from 29 field readings (20112011) via the EPA Water Quality Portal. See the full Little Gabbro Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth26 ft
Surface Area148 acres
Shoreline Length7.7 mi
Littoral Zone79%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
428 sq mi
Elevation
1,440 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Little Gabbro Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2016-09-12 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Tullibee (Cisco)5.580.35 lb
Walleye3.500.8 lb
Yellow Perch3.000.17 lb
White Sucker1.921.43 lb
Northern Pike1.832.03 lb
Rock Bass1.170.45 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

Tullibee (Cisco)

7 fish · 813 in · 2016-09-12
2108910111213

Walleye

16 fish · 920 in · 2016-09-12
63091011121314151617181920

Yellow Perch

18 fish · 59 in · 2016-09-12
63056789

White Sucker

7 fish · 819 in · 2016-09-12
2108910111213141516171819

From the 2016-09-12 survey

Little Gabbro Lake is located approximately 11 miles SE of Ely within the BWCAW. The primary access is a 200 rod portage from a parking area located off the Spruce Road. There are 3 designated campsites located on the lake and another one located in the narrows between Little Gabbro and Gabbro Lakes. Seven species of…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Little Gabbro Lake. 2 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Reservoir Info (USACE NID)

Little Gabbro Lake is a man-made reservoir impounded by the Gabbro Lake 2 (completed 1924), built primarily for recreation on the Isabella River; rockfill-type dam, 7 ft tall and 305 ft long.

Surface area
154 ac
Normal storage
10,300 ac-ft
Max storage
10,300 ac-ft
Drainage area
4.9 sq mi
Hazard class
Low
Owner
USDA FS

Source: USACE National Inventory of Dams, NID ID MN00647 · Operator website · Matched by proximity (0.64 km)

EPA Impairment Status

Little Gabbro Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit MN38-0701-00 · Official waterbody report · Matched by proximity (2.28 km)

Graded lakes near Little Gabbro Lake

Little Gabbro Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Lake County

Frequently asked questions about Little Gabbro Lake

What is the water quality grade for Little Gabbro Lake?

Little Gabbro Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.5 ft visibility. Maximum depth: 26 ft. Surface area: 147.54 acres.

Is Little Gabbro Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Little Gabbro Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

What is the water temperature of Little Gabbro Lake?

Little Gabbro Lake typically sits around 70°F at the surface in July, from 29 EPA Water Quality Portal field readings (2011–2011). That is a typical value for the month, not a live reading.

How deep is Little Gabbro Lake?

Little Gabbro Lake has a maximum depth of 26 feet. The lake covers 147.54 acres.

What fish are in Little Gabbro Lake?

Fish species found in Little Gabbro Lake include black crappie, northern pike, rock bass, tullibee (cisco), walleye, white sucker, yellow perch. Little Gabbro Lake is located in Lake County, Minnesota.

State Parks Near Little Gabbro Lake

Where this data comes from

1 measurement from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA1 sample · 2021

Analytical methods

  • Field measurement/observation, generic method
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder