Side Lake
Side Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.5 ft visibility. Phosphorus: 11.5 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 32 ft. Surface area: 368.22 acres.
- Clarity
- 11.5 ft
- Typical in August
- 63°F
- Max depth
- 32 ft
- Area
- 368 acres
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- Yes
- Ice-out
- Apr 25
- Open water
- 209 days
Next lake in St. Louis County
Side Lake is a 368-acre mesotrophic lake in St. Louis County, Minnesota with a maximum depth of 32 feet. Water quality is graded A based on 2 sampling years through 2025. The lake supports 15 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, Side Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-27. Grade methodology: LakeGrade methodology.
Watch Side Lake water quality
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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)
Good clarity, visible to about 11.5 ft. Phosphorus level: 11.5 µg/L. Chlorophyll-a: 4 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | Not graded |
| Phosphorus | 11.5 µg/L | Good |
| Chlorophyll-a (Algae) | 4 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Side Lake
Compare lakeside cabins, hotels, and vacation rentals near Side 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.
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Water Temperature
Side Lake typically sits around 63°F at the surface in August. Summer average is about 61°F. Usually warmest in Aug (about 63°F) and coldest in May (about 51°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 72 field readings (2018–2025) via the EPA Water Quality Portal. See the full Side Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 32 ft |
| Surface Area | 368 acres |
| Shoreline Length | 4 mi |
| Littoral Zone | 42% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Side LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Side Lake
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2023-07-10 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 9.52 | 1.23 lb |
| Bluegill | 9.27 | 0.17 lb |
| Largemouth Bass | 7.31 | 1.38 lb |
| Northern Pike | 5.03 | 1.47 lb |
| White Sucker | 3.24 | 2.34 lb |
| Yellow Perch | 2.04 | 0.17 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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.
Tullibee (Cisco)
Bluegill
Largemouth Bass
Northern Pike
From the 2023-07-10 survey
Side Lake is a moderately-sized (372 acre) lake located on the Sturgeon Chain of Lakes near Side Lake, Minnesota. Side Lake has relatively clear water, modest fertility and low alkalinity. These characteristics result in good water quality but limit fish production. The lake includes shoreline within McCarthy Beach…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Side Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SideFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Side (1768)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — SideFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — SidePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.013 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (25 observations).
Estimated open water season: 209 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-26 (2012) | 2013-05-14 (2013) |
| Ice-In | 2002-11-15 (2002) | 2021-11-25 (2021) |
Most recent ice-out: 2024-04-07
EPA Impairment Status
Side Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0933-00 · Official waterbody report
County Ranking
Ranked #9 of 68 lakes in St. Louis County
Nearby Lakes in St. Louis County
Frequently asked questions about Side Lake
What is the water quality grade for Side Lake?
- Side Lake in St. Louis County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.5 ft visibility. Phosphorus: 11.5 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 32 ft. Surface area: 368.22 acres.
Is Side Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Side Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Side Lake?
- Side Lake typically sits around 63°F at the surface in August, from 72 EPA Water Quality Portal field readings (2018–2025). That is a typical value for the month, not a live reading.
How deep is Side Lake?
- Side Lake has a maximum depth of 32 feet. The lake covers 368.22 acres.
What fish are in Side Lake?
- Fish species found in Side Lake include black crappie, bluegill, brown bullhead, golden redhorse, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, silver redhorse, tullibee (cisco), walleye, white sucker, yellow perch. Side Lake is located in St. Louis County, Minnesota.
When does Side Lake thaw?
- Side Lake typically has ice-out around Apr 25. Ice typically forms around Nov 20. The open water season is approximately 209 days.
Are there boat ramps on Side Lake?
- Side Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Side Lake. Public access is listed as yes.
Explore Side Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in St. Louis County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Lake Vermilion Area area
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Lakes in the Rainy Lake Watershed, ranked by water quality
Moderate nutrients, good water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Side Lake
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
32 measurements from 2 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
MNPCA32 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 (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
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