Some of these decisions are not final. 1 of these 14 records carry a verdict Wyoming decided in its 2024 Integrated Report, which carries an interim EPA action, so they can change before EPA takes final action on the cycle. They are counted in every figure on this page.
State water-quality picture · #48 by reported lake-type waterbodies
Wyoming lakes and reservoirs
Every figure on this page is computed from the assessment decisions Wyoming reported to the U.S. Environmental Protection Agency under Clean Water Act sections 303(d) and 305(b) (reporting cycles 1998–2024), plus daily water-level observations from the U.S. Geological Survey.
- 14
- Reported waterbodies
- 7
- Not supporting a use
- 0
- Fish use not supporting
- 0
- Gauged lakes
Wyoming in one line
14 lake-type waterbodies in Wyoming are reported to EPA ATTAINS across reporting cycles 1998–2024: 7 assessed as not supporting at least one designated use, 6 fully supporting, and 1 without a definitive overall verdict. The most-listed impairment cause is Selenium, on 4 waterbodies.
- 14
- reported waterbodies
- 7
- not supporting a use
- 6
- fully supporting
- 0
- lakes with a linked USGS gauge
An unassessed waterbody is neither confirmed clean nor confirmed impaired; states assess on multi-year cycles.
Wyoming's smaller reported lake-type inventory
At 14 units, Wyoming is in the lowest third of state lake-type registers. The charts below describe that compact filing set, not a national-scale inventory.
Data updated 2026-08-17
According to the U.S. Environmental Protection Agency's ATTAINS program, Wyoming reported 14 lake-type waterbodies in Wyoming in the August 2026 extract. See our methodology for filer attribution and multi-year reporting cycles.
Overall-status split on Wyoming's compact register
Every reported lake-type unit in this smaller Wyoming filing set falls into exactly one overall-status bucket. The bar partitions 14 units; cause and gauge panels below stay separate.
Most-listed impairment causes in Wyoming
Waterbodies carrying each listed cause, most first
- Selenium
Selenium
4 waterbodies
- Sedimentation/Siltation
Sedimentation/Siltation
2 waterbodies
- Nutrients 1
Nutrients
1 waterbodies
- Phosphate 1
Phosphate
1 waterbodies
- pH 1
pH
1 waterbodies
What this shows Selenium is the most-listed impairment cause in Wyoming, on 4 of the lake-type waterbodies reported there.
Assessment outcomes in Wyoming
Overall-status mix across reported lake-type waterbodies
- Not supporting a use
Not supporting a use
7 waterbodies
- Fully supporting
Fully supporting
6 waterbodies
- No definitive verdict 1
No definitive verdict
1 waterbodies
What this shows Most reported waterbodies in Wyoming do not yet carry a definitive overall verdict.
By size
Largest assessed lakes in Wyoming
By assessed acreage as reported in ATTAINS. Acreage is the assessed unit's size, which can differ from a lake's full surface area.
| # | Waterbody | Assessed acres |
|---|---|---|
| 1 | Boysen Reservoir Not Assessed | 19,387 |
| 2 | Glendo Reservoir Fully Supporting | 12,050 |
| 3 | Ocean Lake Not Supporting | 6,076 |
| 4 | Brooks Lake Not Supporting | 209 |
| 5 | Meeboer Lake Fully Supporting | 116 |
| 6 | Rasmus Lee Lake Not Supporting | 85 |
| 7 | Thirty-three Mile Reservoir Not Supporting | 30 |
| 7 | Goose Lake Not Supporting | 30 |
| 9 | Shirley Basin Reservoir Fully Supporting | 16 |
| 10 | Gillette Fishing Lake Not Supporting | 15 |
| 11 | Miller Lake Fully Supporting | 7.60 |
| 12 | Hanging Lake Fully Supporting | 3.80 |
2 of the 12 rows in this table tie on the ranked value: 2 at 30 (rank 7). Tied rows share a rank and are listed in no meaningful order.
By cause count
Most-listed waterbodies in Wyoming
Waterbodies carrying the most listed impairment causes among the lake-type units reported by Wyoming.
| # | Waterbody | Listed causes |
|---|---|---|
| 1 | Brooks Lake Not Supporting | 2 |
| 1 | Gillette Fishing Lake Not Supporting | 2 |
| 3 | Goose Lake Not Supporting | 1 |
| 3 | Illco Pond Not Supporting | 1 |
| 3 | Ocean Lake Not Supporting | 1 |
| 3 | Rasmus Lee Lake Not Supporting | 1 |
| 3 | Thirty-three Mile Reservoir Not Supporting | 1 |
Every row in this table ties with at least one other on the ranked value: 2 at 2 (rank 1), 5 at 1 (rank 3). Tied rows share a rank and are listed in no meaningful order; where a tie reaches the top the medal is shared, because nothing separates those rows.
States with similar inventory scale or impairment load
Two EPA ATTAINS peer sets outside Wyoming. The reporting-practice chart above stays on definitive-verdict share; these neighborhoods are cross-state nearest neighbors on register size and not-supporting counts.
States with a similar reported inventory
Nearest states by lake-type units on the register (14 here).
Similar not-supporting load
Nearest states by units assessed not supporting a use (7 here). Inventory peers above are omitted.
- Alaska · 7 not supporting · 0 off
- Mississippi · 14 not supporting · 7 off
- Maine · 31 not supporting · 24 off
- Arizona · 34 not supporting · 27 off
Peers are nearest-neighbor matches on EPA ATTAINS register size and not-supporting counts among states with at least 25 reported units. Impairment peers skip states already listed in the inventory column so the two link sets stay distinct.
Using this state picture
- Assessment coverage varies by state; Wyoming's reported universe reflects its own monitoring program, so cross-state comparisons need the definitive-verdict share, not raw counts. National rankings
- Fish-consumption verdicts here are assessment decisions. Species-level meal advice comes from the state fish-advisory program. Consumption guide
- Browse every named Wyoming waterbody with a populated record. Browse waterbodies
PlainLakes renders state assessment decisions and federal gauge observations without modification.
Figures on this page are computed from the assessment decisions Wyoming reported to EPA's ATTAINS system and from USGS National Water Information System daily values, no number is typed in by an editor. State counts aggregate every lake-type assessment unit reported by Wyoming, including unnamed units that never receive their own page. 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.