Crooked Lake
Crooked Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9 ft visibility. Maximum depth: 165 ft. Surface area: 10359.52 acres.
- Clarity
- 9 ft
- Max depth
- 165 ft
- Area
- 10,360 acres
- Trend
- ↓ Declining
- Public access
- No
Next lake in Lake County
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, 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.
Crooked Lake is a 10,360-acre lake in Lake County, Minnesota with a maximum depth of 165 feet (37-foot average). Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-06-24. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Crooked Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 9 ft. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Crooked Lake
Compare lakeside cabins, hotels, and vacation rentals near Crooked 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 165 ft |
| Average Depth | 37 ft |
| Surface Area | 10,360 acres |
| Shoreline Length | 231.7 mi |
| Littoral Zone | 18% |
| Public Access | No |
Fishing Crooked Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2025-08-01 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 7.34 | 0.37 lb |
| Walleye | 4.84 | 1.19 lb |
| Northern Pike | 3.96 | 3.04 lb |
| White Sucker | 2.33 | 2.1 lb |
| Yellow Perch | 1.21 | 0.17 lb |
| Rock Bass | 1.20 | 0.41 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)
Walleye
Northern Pike
White Sucker
From the 2025-08-01 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Crooked Lake on August 1st, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Whitefish, the most sensitive coldwater species present in this lake (Cisco, also…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Crooked Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — CrookedFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.436 m/yr | 5 |
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN38-0817-00 · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Crooked Lake
What is the water quality grade for Crooked Lake?
- Crooked Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9 ft visibility. Maximum depth: 165 ft. Surface area: 10359.52 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 165 feet and an average depth of 37 feet. The lake covers 10359.52 acres.
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Where this data comes from
53 measurements from 23 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA53 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (23)
- MNPCA-38-0817-00-100
- MNPCA-38-0817-00-234
- MNPCA-38-0817-00-221
- MNPCA-38-0817-00-222
- MNPCA-38-0817-00-212
- MNPCA-38-0817-00-232
- MNPCA-38-0817-00-218
- MNPCA-38-0817-00-213
- MNPCA-38-0817-00-237
- MNPCA-38-0817-00-203
- MNPCA-38-0817-00-215
- MNPCA-38-0817-00-240
- MNPCA-38-0817-00-230
- MNPCA-38-0817-00-219
- MNPCA-38-0817-00-214
- MNPCA-38-0817-00-241
- MNPCA-38-0817-00-227
- MNPCA-38-0817-00-223
- MNPCA-38-0817-00-228
- MNPCA-38-0817-00-231
- MNPCA-38-0817-00-216
- MNPCA-38-0817-00-201
- MNPCA-38-0817-00-208
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 details from Minnesota DNR LakeFinder