Maple Lake
Maple Lake in Itasca County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15.3 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 39 ft. Surface area: 254.55 acres.
- Clarity
- 15.3 ft
- Typical in August
- 71°F
- Max depth
- 39 ft
- Area
- 255 acres
- Type
- Oligotrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Itasca County
Maple Lake is a 255-acre cold, clear oligotrophic lake in Itasca County, Minnesota with a maximum depth of 39 feet. Water quality is graded A based on 2 sampling years through 2020. Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 2 public boat landings. Compared to the 71 other monitored lakes in Itasca County, Maple Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2020-09-24. 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 15.3 ft down. Phosphorus level: 11 µg/L. Chlorophyll-a: 3.2 µg/L. Trophic State Index: 40.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 15.3 ft | Not graded |
| Phosphorus | 11 µg/L | Good |
| Chlorophyll-a (Algae) | 3.2 µg/L | Good |
| Trophic State Index (TSI) | 40 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Maple Lake
Compare lakeside cabins, hotels, and vacation rentals near Maple Lake in Itasca 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
Maple Lake typically sits around 71°F at the surface in August. Summer average is about 69°F. Usually warmest in Jul (about 73°F) and coldest in Jun (about 63°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 14 field readings (2017–2021) via the EPA Water Quality Portal. See the full Maple Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Maple Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (8,091 cells/mL) on April 25, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 39 ft |
| Surface Area | 255 acres |
| Shoreline Length | 3.5 mi |
| Littoral Zone | 30% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Maple LakePublic
- Turtle LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Maple Lake
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2021-07-21 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 13.96 | 0.16 lb |
| Largemouth Bass | 6.66 | 0.99 lb |
| Bluntnose Minnow | 5.16 | — |
| Tullibee (Cisco) | 5.11 | 1.14 lb |
| Northern Pike | 4.22 | 1.3 lb |
| Yellow Perch | 3.86 | 0.15 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.
Bluegill
Largemouth Bass
Tullibee (Cisco)
Northern Pike
From the 2021-07-21 survey
A targeted survey of nearshore fish species in Maple Lake was conducted on July 21-22, 2021, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Maple Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MapleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Maple (0705)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — MapleFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MaplePublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.2 m/yr | 4 |
| Phosphorus | ↑ Improving | -0.65 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -0.31 µg/L/yr | 4 |
EPA Impairment Status
Maple 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 MN31-0725-00 · Official waterbody report · Matched by proximity (1.91 km)
County Ranking
Ranked #3 of 72 lakes in Itasca County
Nearby Lakes in Itasca County
Frequently asked questions about Maple Lake
What is the water quality grade for Maple Lake?
- Maple Lake in Itasca County, Minnesota has a water quality grade of A (Excellent). Water clarity: 15.3 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 39 ft. Surface area: 254.55 acres.
Is Maple Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Maple Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.2 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Maple Lake?
- Maple Lake typically sits around 71°F at the surface in August, from 14 EPA Water Quality Portal field readings (2017–2021). That is a typical value for the month, not a live reading.
How deep is Maple Lake?
- Maple Lake has a maximum depth of 39 feet. The lake covers 254.55 acres.
What fish are in Maple Lake?
- Fish species found in Maple Lake include black crappie, bluegill, bowfin (dogfish), largemouth bass, northern pike, pumpkinseed, rock bass, sunfish, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Maple Lake is located in Itasca County, Minnesota.
Does Maple Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Maple Lake (clouds, ice, or an off-season gap). The most recent reading was low (8,091 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Maple Lake?
- Maple Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Maple Lake, Turtle Lake. Public access is listed as yes.
Explore Maple Lake across LakeGrade
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Where this data comes from
15 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA15 samples · 2020
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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.
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