Little Rock Lake
Little Rock Lake in Clearwater County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15.1 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 3 µg/L.
- Clarity
- 15.1 ft
- Type
- Oligotrophic
Next lake in Clearwater County
Little Rock Lake is a cold, clear oligotrophic lake in Clearwater County, Minnesota. Water quality is graded A based on 2 sampling years through 2025. Compared to the 36 other monitored lakes in Clearwater County, Little Rock Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-04. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 15.1 ft down. Phosphorus level: 9.5 µg/L. Chlorophyll-a: 3 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.1 ft | Not graded |
| Phosphorus | 9.5 µg/L | Good |
| Chlorophyll-a (Algae) | 3 µg/L | Good |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Little Rock Lake
Compare lakeside cabins, hotels, and vacation rentals near Little Rock Lake in Clearwater 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 Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Little Rock Lake
County Ranking
Ranked #10 of 37 lakes in Clearwater County
Nearby Lakes in Clearwater County
Frequently asked questions about Little Rock Lake
What is the water quality grade for Little Rock Lake?
- Little Rock Lake in Clearwater County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15.1 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 3 µg/L.
Is Little Rock Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Little Rock Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3 µg/L. Always check local health department advisories before swimming.
How deep is Little Rock Lake?
- The available depth estimate for Little Rock Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown.
Explore Little Rock Lake across LakeGrade
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Low nutrients, clear water, excellent for swimming
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Where this data comes from
34 measurements from 2 monitoring stations, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Chippewa Tribe, Minnesota (White Earth Band) (Tribal)
WEARTH_WQX34 samples · 2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)