Skip to main content
LakeQuality

Dark Lake

NR
Not yet rated
3.8 ft clear · Eutrophic · 231 acres
Limited DataEutrophic

Dark Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.8 ft visibility. Maximum depth: 31 ft. Surface area: 230.98 acres.

Clarity
3.8 ft
Typical in August
63°F
Max depth
31 ft
Area
231 acres
Public access
Yes

Next lake in St. Louis County

BLittle Sandy LakeSt. Louis CountyView →
Loading map…

Why Dark 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 Dark Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. 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.

Dark Lake is a 231-acre lake in St. Louis County, Minnesota with a maximum depth of 31 feet. The lake supports 10 documented fish species including black crappie, bluegill, and largemouth bass. Public access is available with 2 public boat landings.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-08. Grade methodology: LakeGrade methodology.

Watch Dark Lake water quality

Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.

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 Grand Rapids

Get alerts for Dark Lake

Water quality measurements for Dark Lake

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

Murky, only visible to about 3.8 ft. Trophic State Index: 58.

MetricValueGrade
Water Clarity (Secchi Depth)3.8 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)58Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Dark Lake

Compare lakeside cabins, hotels, and vacation rentals near Dark Lake in St. Louis 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 Dark 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

Dark Lake typically sits around 63°F at the surface in August. Summer average is about 61°F. Usually warmest in Aug (about 63°F) and coldest in May (about 50°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
50°
Jun
58°
Jul
61°
Aug
63°
Sep
59°
Oct
56°
Nov
Dec

Typical surface water temperature by month, from 130 field readings (20112024) via the EPA Water Quality Portal. See the full Dark Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth31 ft
Surface Area231 acres
Shoreline Length3.9 mi
Littoral Zone60%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
32 sq mi
Elevation
1,391 ft

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

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Mud (Knuckley) LakePublic
  • Dark LakePublic

Fish Species

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

Fishing Dark Lake

EPA Impairment Status

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

Causes of impairment

MercurySalinity / chlorides

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN69-0790-00 · Official waterbody report

Graded lakes near Dark Lake

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

Nearby Lakes in St. Louis County

Frequently asked questions about Dark Lake

What is the water quality grade for Dark Lake?

Dark Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.8 ft visibility. Maximum depth: 31 ft. Surface area: 230.98 acres.

Is Dark Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Dark 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 Dark Lake?

Dark Lake typically sits around 63°F at the surface in August, from 130 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.

How deep is Dark Lake?

Dark Lake has a maximum depth of 31 feet. The lake covers 230.98 acres.

What fish are in Dark Lake?

Fish species found in Dark Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, walleye, white sucker, yellow perch. Dark Lake is located in St. Louis County, Minnesota.

Are there boat ramps on Dark Lake?

Dark Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mud (Knuckley) Lake, Dark Lake. Public access is listed as yes.

Where this data comes from

63 measurements from 2 monitoring stations, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA63 samples · 2024

Analytical methods

  • Field measurement/observation, generic method
Monitoring station identifiers (2)

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

Named boat-access points from the USGS National Boat Ramps inventory