Oklahoma lake · tribal assessment record
Lake Murray (5,700 acres)
Assessment decisions reported by The Chickasaw Nation to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2025 reporting cycle.
- 5,700
- Assessed acres
- Lake
- Water type
This waterbody in one line
Lake Murray, a lake in Oklahoma, is assessed as not supporting one or more designated uses, with one listed impairment cause in the Chickasaw Nation's most recent Integrated Report cycle (2025). 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
- P99
- Assessed size nationally
- P20
- Shorter cause list
- Not Supporting
- aquatic life
Assessment verdicts are the Chickasaw Nation'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.
Where Lake Murray stands in the filed register
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 Murray nationally is assessed size: 5,700 acres, larger than 99% of the 38,628 lake-type units with an area on file.
Every filed use falls short
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 Murray 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, Oklahoma carries 456 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake Murray 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 Chickasaw Nation's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle. The latest monitoring the Chickasaw Nation filed against this record runs through 2025. For the one definitive verdict on this record, the Chickasaw Nation filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them.
| Designated use | Group | Verdict |
|---|---|---|
| Aquatic Life | Aquatic-life or related | Not Supporting |
| Primary Contact | Recreation | Insufficient Information |
The record
Listed impairment causes
Causes the Chickasaw Nation 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 |
|---|---|---|---|
| Temperature | Aquatic Life | 2025 | None reported |
Reading the record
Where Lake Murray sits among peers
50% of Oklahoma's lakes assessed this deeply also had no use supported
The Chickasaw Nation ruled definitively on a single designated use at Lake Murray and found it not supported. The dataset shows 26 Oklahoma lakes judged to that same depth.
Oklahoma's assessed lakes are most often judged on 5 or more uses; this one was judged on 1.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 13 | 8 | 7 | 8 | 9 |
| Mixed | Not possible | 6 | 12 | 30 | 92 |
| None supported | 13 (this record) | 0 | 0 | 0 | 0 |
Ringed cell: Lake Murray. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake Murray is one of 456 lake-type waterbodies reported to EPA from Oklahoma, and one of 173 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 5,700 assessed acres it ranks 546th 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 545 lakes with a larger one.
Awaiting a filing
The Chickasaw Nation 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 Murray has no daily USGS water-level or reservoir-storage series on this page because NWIS lists a lake monitoring site named for the waterbody, but the site is not active, and PlainLakes ingests only the active inventory, so there is no series to attach. How PlainLakes links gauges.
In context
Where Lake Murray 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
5,700 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 Murray. Hover or tap any bar for its full count and share.
In context
Oklahoma context
ATTAINS carries 456 lake-type waterbodies in Oklahoma, 153 assessed as not supporting at least one use and 45 fully supporting. Among the 173 indexed units there, Lake Murray ranks 112th by listed-cause count (one listed cause) and 42nd by assessed size among the 170 with an area filed; it sits in the not-supporting set (153 statewide) . Its listed causes (Temperature) sit outside Oklahoma's top-five list, which is led by Mercury.
| Other large assessed lakes in Oklahoma | Assessed acres |
|---|---|
| Grand Lake Site 12 Not Supporting | 46,500 |
| Grand Lake Site 13 Not Supporting | 46,500 |
| Grand Lake Site 14 Fully Supporting | 46,500 |
| Grand Lake Site 15 Fully Supporting | 46,500 |
| Robert S. Kerr Lake Not Supporting | 43,380 |
| Texoma Lake, Red River Arm, Lower Not Supporting | 31,081 |
Peers near Lake Murray's size or cause load
Similar assessed acres
Nearest filed extents (5,700 acres here).
- Lewisville Lake · 5,701 acres · TX
- Lake Kemp · 5,696 acres · TX
- South Lake Leelanau · 5,694 acres · MI
- McClure Reservoir (Mariposa County) · 5,691 acres · CA
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- 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
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 Chickasaw Nation's reported decisions for assessment unit LMLove. 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.