Skip to main content
LakeQuality

Crooked Lake

NR
Not yet rated
5.5 ft clear · Eutrophic · 244 acres
Limited DataEutrophic

Crooked Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.5 ft visibility. Maximum depth: 66 ft. Surface area: 244.35 acres.

Clarity
5.5 ft
Max depth
66 ft
Area
244 acres
Trend
Declining
Public access
No

Next lake in Cook County

NRTarry Lake13 ft clear · Cook CountyView →
Loading map…

Why Crooked 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 Crooked 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.

Crooked Lake is a 244-acre lake in Cook County, Minnesota with a maximum depth of 66 feet. Overall water quality is declining over recent sampling years. The lake supports 3 documented fish species including burbot, lake trout, and white sucker. No public access — the lake is private or restricted.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-06. Grade methodology: LakeGrade methodology.

Watch Crooked 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 Ely

Get alerts for Crooked Lake

Water quality measurements for Crooked Lake

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

Murky, only visible to about 5.5 ft. Trophic State Index: 53.

MetricValueGrade
Water Clarity (Secchi Depth)5.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)53Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Crooked Lake

Compare lakeside cabins, hotels, and vacation rentals near Crooked Lake in Cook 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 Crooked 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 →

Lake Details

CharacteristicValue
Maximum Depth66 ft
Surface Area244 acres
Shoreline Length9.1 mi
Littoral Zone45%
Public AccessNo

Lake Size & Watershed

Watershed (drainage) area
24 sq mi
Elevation
1,640 ft

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

Fish Species

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

Fishing Crooked Lake

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.76 m/yr2

EPA Impairment Status

Crooked Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Mercury

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

Source: EPA ATTAINS assessment unit MN16-0723-00 · Official waterbody report

Nearby Lakes in Cook County

Frequently asked questions about Crooked Lake

What is the water quality grade for Crooked Lake?

Crooked Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.5 ft visibility. Maximum depth: 66 ft. Surface area: 244.35 acres.

Is Crooked Lake safe to swim in?

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

How deep is Crooked Lake?

Crooked Lake has a maximum depth of 66 feet. The lake covers 244.35 acres.

What fish are in Crooked Lake?

Fish species found in Crooked Lake include burbot, lake trout, white sucker. Crooked Lake is located in Cook County, Minnesota.

Eutrophic Lakes in Minnesota

Where this data comes from

1 measurement from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA1 sample · 2025

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