Blacks Fork Lake
Sweetwater County, WyomingView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- Limited data
Blacks Fork Lake in Sweetwater County, Wyoming is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility.
- Clarity
- 8.5 ft
- Trend
- ↑ Improving
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Watch Blacks Fork Lake’s letter
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Why Blacks Fork Lake has no grade
Blacks Fork Lake has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Blacks Fork Lake is Not Rated — not an F. Its 8.5-foot median from 13 readings collected 2012–2016 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. Everything below that has been measured is still reported on this page.
Sampling is run by Wyoming DEQ and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Blacks Fork Lake is a lake in Sweetwater County, Wyoming. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2016-07-05. Grade methodology: LakeQuality methodology.
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Blacks Fork Lake
These readings exist but are not enough for an A–F grade — see why.
Moderate clarity, visible to about 8.5 ft. TSI 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Fishing Blacks Fork Lake
Water Quality Trend: ↑ Improving
Based on 10 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.162 m/yr | 9 |
| Phosphorus | ↑ Improving | -1.21 µg/L/yr | 10 |
| Chlorophyll-a | ↑ Improving | -0.2 µg/L/yr | 4 |
Graded lakes near Blacks Fork Lake
Blacks Fork Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Sweetwater County
Frequently asked questions about Blacks Fork Lake
Where is Blacks Fork Lake?
- Blacks Fork Lake is a lake in Sweetwater County, Wyoming. LakeQuality has not rated this lake (UNRATED) — 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.
What is the water quality grade for Blacks Fork Lake?
- Blacks Fork Lake in Sweetwater County, Wyoming is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.5 ft visibility.
Is Blacks Fork Lake safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
Explore Blacks Fork Lake across LakeQuality
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Where this data comes from
13 measurements from 1 monitoring station, 2012–2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- UC Region of USBOR
UC_REGION_USBOR_WQX13 samples · 2012–2016
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.