Ely Lake
St. Louis County, Minnesota723 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Ely Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- zebra mussel
- 70 ft max depth
- Public access
- Limited data
Ely Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17.1 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 70 ft. Surface area: 723.09 acres.
Minnesota DNR's Targeted Survey on August 25, 2025 caught 2.57 largemouth bass per hour of electrofishing at Ely Lake. Length samples in the latest survey that recorded them ran 5–15 inches. DNR survey details →
Ely Lake is a 723-acre cold, clear oligotrophic lake in St. Louis County, Minnesota with a maximum depth of 70 feet. Overall water quality is improving over recent sampling years. The lake supports 14 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in St. Louis County, Ely Lake ranks #20 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-10. Methodology: how these readings are compared.
Ely Lake covers about 720 acres in St. Louis County. It has one public boat landing. The median ice-out date is April 24, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Ely Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Ely Lake is good for
From access and monitoring records, not editorial picks.
- Clear water17.1 ft of visibility
- Boat launch1 documented ramp
- Fishing14 species recorded
- Ice seasonIce-out around Apr 24
- Deep water70 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
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. Ely Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Ely 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 Ely Lake
These are the measurements Minnesota PCA publishes for Ely Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 17.1 ft down. Phosphorus 7 µg/L. Chlorophyll-a 2.1 µg/L. TSI 35.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 17.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 7µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 35 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Ely Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Ely Lake typically sits around 61°F at the surface in October. Summer average is about 71°F. Usually warmest in Aug (about 75°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (75°F).
Typical surface water temperature by month, from 47 field readings (2022–2025) via the EPA Water Quality Portal. See the full Ely Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on August 25, 2025 caught 2.57 largemouth bass per hour of electrofishing at Ely Lake. Length samples in the latest survey that recorded them ran 5–15 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ely Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
13 surveys on file from MN DNR Fisheries. Most recent: 2025-08-25 (Targeted Survey).
13 surveys on file · most recent 2025-08-25 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 21.38 | 3–8 in 2023-08-14 | 0.14 lb |
| Bluntnose Minnow | 14.57 | ||
| Hybrid Sunfish | 9.28 | 3–8 in 2023-08-14 | 0.31 lb |
| Largemouth Bass | 8.32 | 5–15 in 2023-08-14 | 0.58 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.
Bluegill
Hybrid Sunfish
Largemouth Bass
From the 2025-08-25 survey
A targeted survey of nearshore fish species in Ely Lake was conducted on August 25th-August 28th, 2025, by Lake Biological Monitoring and Assessment (LBMA) program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing, mini-fyke nets, and seining with a 50-foot or…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ely Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ElyFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Ely (1771)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — ElyFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — ElyPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
70 ft
Surface area
723 acres
Shoreline
9.6 mi
Littoral zone
31%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
5 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,368 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Ely 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 Ely Lake
Compare lakeside cabins, hotels, and vacation rentals near Ely Lake in St. Louis 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.
Top-rated places to stay near Ely 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 →
Follow Ely Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Ely Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Ice season
Typical ice-out
Apr 24
Earliest Apr 5, 2000 · Latest May 9, 1996
Typical ice-in
Nov 24
Earliest Nov 5, 1991 · Latest Dec 20, 2018
Most recent ice-out
May 6
2022
74 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Ely Lake is a man-made reservoir impounded by the Ely Lake (completed 1939), built primarily for recreation on the Ely Creek; gravity-type dam, 8 ft tall and 34 ft long.
- Surface area
- 780 ac
- Normal storage
- 55,620 ac-ft
- Max storage
- 61,182 ac-ft
- Drainage area
- 10 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN00005 · Operator website
EPA Impairment Status
Ely Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0660-00 · Official waterbody report
Nearby Lakes in St. Louis County
Frequently asked questions about Ely Lake
Where is Ely Lake?
- Ely Lake is a lake in St. Louis County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Ely Lake?
- Ely Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17.1 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 70 ft. Surface area: 723.09 acres.
Is Ely Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Ely Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
What is the water temperature of Ely Lake?
- Ely Lake typically sits around 61°F at the surface in October, from 47 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Ely Lake?
- Ely Lake has a maximum depth of 70 feet. The lake covers 723.09 acres.
What fish are in Ely Lake?
- Fish species found in Ely Lake include black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Ely Lake is located in St. Louis County, Minnesota.
What did the DNR fisheries survey find at Ely Lake?
- Minnesota DNR's Targeted Survey on August 25, 2025 caught 2.57 largemouth bass per hour of electrofishing at Ely Lake. Length samples in the latest survey that recorded them ran 5–15 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ely Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Ely Lake thaw?
- Ely Lake typically has ice-out around Apr 24. Ice typically forms around Nov 24. The open water season is approximately 214 days.
Are there boat ramps on Ely Lake?
- Ely Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ely Lake. Public access is listed as yes.
Can I fish at Ely Lake?
- Ely 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 Ely Lake across LakeQuality
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Fish species and best lakes in St. Louis County
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Where this data comes from
78 measurements from 3 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA78 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 (3)
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
Ice data from Minnesota DNR Climate