Mantrap Lake
Hubbard County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Mantrap Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- Eurasian watermilfoil
- 77 ft max depth
- Public access
Mantrap Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 4.5 µg/L.
Mantrap Lake is a mesotrophic lake in Hubbard County, Minnesota with an estimated average depth of about 77 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 67 other monitored lakes in Hubbard County, Mantrap Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-27. Methodology: how these readings are compared.
Mantrap Lake has 2 public boat landings, so a lakefront rental is not the only way to get a boat on the water. Vrbo is where to look for cabins and lake homes around Mantrap Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Mantrap Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12 ft of visibility
- Boat launch2 documented ramps
Swimming conditions
Readings onlyLow algae
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. Mantrap Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Mantrap 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 Mantrap Lake
These are the measurements Minnesota PCA publishes for Mantrap Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12 ft. Phosphorus 17 µg/L. Chlorophyll-a 4.5 µg/L. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 17µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.5µg/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. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Mantrap Lake
Answers come straight from the public measurements and survey records on this page.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mantrap Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — Mantrap (Middle Basin)Public Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
~77 ft est.
Public access
Yes
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Mantrap Lake.
Lake Size & Watershed
Watershed (drainage) area
31 sq mi
HydroLAKES / HydroSHEDS
Surface area
1,525 acres
HydroLAKES / HydroSHEDS
Shoreline
22.7 mi
HydroLAKES / HydroSHEDS
Elevation
1,424 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Mantrap LakePublic
- Mantrap 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 Mantrap Lake
Compare lakeside cabins, hotels, and vacation rentals near Mantrap Lake in Hubbard 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 Mantrap Lake
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Fishing Mantrap 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
Phosphorus
Stable-0.31 µg/L/yr6 years
Chlorophyll-a
Improving-0.13 µg/L/yr6 years
EPA Impairment Status
Mantrap 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: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN29-0151-02 · Official waterbody report
Nearby Lakes in Hubbard County
Frequently asked questions about Mantrap Lake
Where is Mantrap Lake?
- Mantrap Lake is a lake in Hubbard County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Mantrap Lake?
- Mantrap Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 12 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 4.5 µg/L.
Is Mantrap Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Mantrap Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Mantrap Lake?
- No published bathymetric survey covers Mantrap Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 77 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Mantrap Lake?
- Mantrap Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Mantrap Lake, Mantrap Lake. Public access is listed as yes.
Can I fish at Mantrap Lake?
- Mantrap Lake has 2 documented boat landings 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 Mantrap Lake across LakeQuality
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Where this data comes from
677 measurements from 8 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
MNPCA677 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 (8)
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