Minnesota lake · tribal assessment record
Lake of the Woods
Part of the Lake of the Woods Watershed in Lake of the Woods County. Assessment decisions reported by Red Lake Band of Chippewa Indians, Minnesota to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.
- 301,348
- Assessed acres
- Lake
- Water type
This waterbody in one line
Lake of the Woods, a lake in Minnesota, is assessed as not supporting one or more designated uses, with one listed impairment cause in the Red Lake Band of Chippewa Indians's most recent Integrated Report cycle (2022). By assessed acreage it sits among the largest 1% of assessed lakes nationally (38,628 lakes with a filed area); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P100
- Assessed size nationally
- P20
- Shorter cause list
- Not Supporting
- aquatic life
Assessment verdicts are the Red Lake Band of Chippewa Indians's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
A composite of this record's EPA ATTAINS designated-use verdicts, filed impairment count, and assessment currency, weighted and benchmarked against the national corpus of assessed active waterbodies. This is a water-quality standing, not a human-recreation or property-value judgment, and dimensions with no filed verdict drop out rather than count against the score.
Reading Lake of the Woods's filed record
Paragraphs are selected by this unit's percentiles and use matrix: different lakes lead with different dimensions. Figures are ATTAINS / portal register arithmetic, not advice.
The signature stat: assessed size
The number that most separates Lake of the Woods nationally is assessed size: 301,348 acres, larger than 100% of the 38,628 lake-type units with an area on file.
Every ruled-on use is not supporting
On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Overall status: not supporting
The filer's overall status for Lake of the Woods is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Typical cause-list length
1 listed cause is a middle-tercile list length among assessed lake-type units. Look to IR category and use outcomes for the distinctive reading.
According to the U.S. Environmental Protection Agency's ATTAINS program, Minnesota carries 13,176 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake of the Woods without modification. See our methodology for reporting-unit limits and gauge linking rules.
The record
Designated-use assessments
Fully Supporting and Not Supporting are the Red Lake Band of Chippewa Indians's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle.
| Designated use | Group | Verdict |
|---|---|---|
| General | Other | Fully Supporting |
| Warm Water Fisheries | Aquatic-life or related | Not Supporting |
| Secondary Contact | Recreation | Insufficient Information |
The record
Listed impairment causes
Causes the Red Lake Band of Chippewa Indians listed as impairing designated uses of this lake, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Phosphorus, Total | Warm Water Fisheries | Not reported | None reported |
Reading the record
Where Lake of the Woods sits among peers
62% of Minnesota's lakes assessed this deeply also came out mixed
The Red Lake Band of Chippewa Indians ruled definitively on 2 designated uses at Lake of the Woods and found 1 of 2 not supported. The dataset shows 854 Minnesota lakes judged to that same depth.
Minnesota's assessed lakes are most often judged on 1 use; this one was judged on 2.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 1.4k | 169 | 7 | 1 | 16 |
| Mixed | Not possible | 526 (this record) | 341 | 17 | 10 |
| None supported | 682 | 159 | 62 | 0 | 0 |
Ringed cell: Lake of the Woods. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake of the Woods is one of 13,176 lake-type waterbodies reported to EPA from Minnesota, and one of 1,939 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 301,348 assessed acres it ranks 10th by assessed size among the 38,628 lakes the dataset carries an area for, counting a state’s repeated filings of one water once, behind 9 lakes with a larger one.
Awaiting a filing
The Red Lake Band of Chippewa Indians has not yet filed a definitive fish-consumption verdict and a definitive recreation verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
Why no water-level record
Lake of the Woods has no daily USGS water-level or reservoir-storage series on this page because a site carries the lake’s name, but that name fits more than one assessed waterbody in the state, and PlainLakes declines it rather than guessing. How PlainLakes links gauges.
In context
Where Lake of the Woods sits nationally
Assessed size among U.S. lakes
Distribution of assessed acreage across ATTAINS lakes filed with an area, counting a state’s repeated filings of one water once
301,348 Top 1% larger than 99%+ of 38,628 lakes
lakes the dataset carries an area for, counting a state’s repeated filings of one water once, bucketed by value
Source EPA ATTAINS · Reporting cycles 1987–2026
Listed causes vs waterbodies carrying a verdict
How many impairment causes U.S. waterbodies with a reported verdict carry
1 Longer than most more listed causes than 49% of 23,610 waterbodies carrying a verdict
named waterbodies carrying a verdict, bucketed by value
Source EPA ATTAINS · Reporting cycles 1987–2026
In both charts each bar is a band and taller bars hold more waterbodies; the dashed line and filled bar mark Lake of the Woods. Hover or tap any bar for its full count and share.
In context
Minnesota context
ATTAINS carries 13,176 lake-type waterbodies in Minnesota, 1,798 assessed as not supporting at least one use and 1,566 fully supporting. Among the 1,939 indexed units there, Lake of the Woods ranks 363rd by listed-cause count (one listed cause) and 2nd by assessed size among the 1,930 with an area filed; it sits in the not-supporting set (1,798 statewide) . Its listed causes (Phosphorus, Total) sit outside Minnesota's top-five list, which is led by Mercury in Fish Tissue.
| Other large assessed lakes in Minnesota | Assessed acres |
|---|---|
| Superior Not Supporting | 13,182,720 |
| Red (Lower Red) Not reported | 164,699 |
| Lower Red Lake Fully Supporting | 164,689 |
| Mille Lacs Not Supporting | 128,076 |
| Red (Upper Red) Not Supporting | 119,279 |
| Upper Red Lake Fully Supporting | 118,943 |
Peers near Lake of the Woods's size or cause load
Similar assessed acres
Nearest filed extents (301,348 acres here).
- Lake Sakakawea · 318,821 acres · ND
- Lake Erie Western Basin Open Water (>3m) · 337,472 acres · OH
- Fort Peck Reservoir · 233,296 acres · MT
- Salton Sea · 233,045 acres · CA
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · NH
- Academy Brook II Dam · 1 causes · NH
What to do with this record
- Assessment verdicts are cycle-based, not real-time. For fish-consumption decisions, your state advisory program is the binding source. Consumption status guide
- Impairment listings follow the Clean Water Act 303(d) process; a listing is a regulatory finding, not a closure notice. 303(d) explained
PlainLakes renders state assessment decisions and federal gauge observations without modification. It does not issue advisories.
Assessment decisions on this page are rendered directly from state Integrated Report records in EPA's ATTAINS system; gauge figures are daily-value observations from the USGS National Water Information System, no number is typed in by an editor. Overall status, use verdicts, and causes are the Red Lake Band of Chippewa Indians's reported decisions for assessment unit RLN_LAKE_OF_THE_WOODS. Counts and percentiles are computed across all lake-type records PlainLakes ingests from ATTAINS. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-17. Primary sources: EPA ATTAINS and USGS National Water Information System.