Rockstad Lake
Clearwater County, Minnesota142 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Rockstad Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 18 ft max depth
- Public access
Rockstad Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.3 ft visibility. Phosphorus: 47.5 µg/L. Chlorophyll-a (algae): 28.9 µg/L. Maximum depth: 18 ft. Surface area: 141.52 acres.
Minnesota DNR's Standard Survey on August 11, 2014 caught 12.50 northern pike per gill net at Rockstad Lake. Length samples in the latest survey that recorded them ran 14–31 inches. DNR survey details →
Rockstad Lake is a 142-acre productive, nutrient-rich eutrophic lake in Clearwater County, Minnesota with a maximum depth of 18 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including black crappie, northern pike, and white sucker. Public access is available with 1 public boat landing. Compared to the 36 other monitored lakes in Clearwater County, Rockstad Lake ranks #36 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-09. Methodology: how these readings are compared.
What Rockstad Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing4 species recorded
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Rockstad Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Rockstad Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rockstad Lake
These are the measurements Minnesota PCA publishes for Rockstad Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 4.3 ft. Phosphorus 47.5 µg/L. Chlorophyll-a 28.9 µg/L. TSI 60.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 47.5µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 28.9µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 60 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Rockstad Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Rockstad Lake typically sits around 62°F at the surface in September. Summer average is about 70°F. Usually warmest in Jul (about 73°F) and coldest in Sep (about 62°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (62°F) to its warmest (73°F).
Typical surface water temperature by month, from 49 field readings (2010–2021) via the EPA Water Quality Portal. See the full Rockstad Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 11, 2014 caught 12.50 northern pike per gill net at Rockstad Lake. Length samples in the latest survey that recorded them ran 14–31 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rockstad Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2014-08-11 (Standard Survey).
5 surveys on file · most recent 2014-08-11 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 148.28 | 6–10 in 2014-08-11 | 0.2 lb |
| Yellow Perch | 144.66 | 4–9 in 2014-08-11 | 0.16 lb |
| White Sucker | 11.79 | 7–17 in 2014-08-11 | 0.87 lb |
| Brown Bullhead | 5.88 | 7–12 in 2014-08-11 | 0.42 lb |
| Walleye | 5.77 | 0.43 lb | |
| Northern Pike | 5.03 | 14–31 in 2014-08-11 | 3.02 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Black Bullhead
Yellow Perch
White Sucker
Brown Bullhead
From the 2014-08-11 survey
Rockstad Lake is a 128-acre lake with a maximum depth of 18 feet located near the town of Zerkel in southern Clearwater County. The Minnesota Department of Natural Resources has classified Minnesota's lakes into 43 different lake classes based on physical characteristics, water chemistry and fish community. Rockstad…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Rockstad Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — RockstadFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Rockstad (1693)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — RockstadPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
18 ft
Surface area
142 acres
Shoreline
2 mi
Littoral zone
86%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,496 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Rockstad LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Rockstad Lake
Compare lakeside cabins, hotels, and vacation rentals near Rockstad 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Rockstad Lake are listed below.
Top-rated places to stay near Rockstad Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Rockstad Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving5 years
Phosphorus
Worsening+1.31 µg/L/yr6 years
Chlorophyll-a
Worsening+1.36 µg/L/yr6 years
EPA Impairment Status
Rockstad Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN15-0075-00 · Official waterbody report
Nearby Lakes in Clearwater County
Frequently asked questions about Rockstad Lake
Where is Rockstad Lake?
- Rockstad Lake is a lake in Clearwater County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Rockstad Lake?
- Rockstad Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4.3 ft visibility. Phosphorus: 47.5 µg/L. Chlorophyll-a (algae): 28.9 µg/L. Maximum depth: 18 ft. Surface area: 141.52 acres.
Is Rockstad Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Rockstad Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Rockstad Lake?
- Rockstad Lake typically sits around 62°F at the surface in September, from 49 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Rockstad Lake?
- Rockstad Lake has a maximum depth of 18 feet. The lake covers 141.52 acres.
What fish are in Rockstad Lake?
- Fish species found in Rockstad Lake include black crappie, northern pike, white sucker, yellow perch. Rockstad Lake is located in Clearwater County, Minnesota.
What did the DNR fisheries survey find at Rockstad Lake?
- Minnesota DNR's Standard Survey on August 11, 2014 caught 12.50 northern pike per gill net at Rockstad Lake. Length samples in the latest survey that recorded them ran 14–31 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rockstad Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Rockstad Lake?
- Rockstad Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Rockstad Lake. Public access is listed as yes.
Can I fish at Rockstad Lake?
- Rockstad Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Rockstad Lake across LakeQuality
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Where this data comes from
76 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA76 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory