Little Mantrap Lake
Hubbard County, Minnesota381 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Little Mantrap Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- 54 ft max depth
- Public access
- Limited data
Little Mantrap Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 54 ft. Surface area: 380.95 acres.
Minnesota DNR's Standard Survey on July 25, 2022 caught 2.67 walleye per gill net at Little Mantrap Lake. DNR survey details →
Little Mantrap Lake is a 381-acre cold, clear oligotrophic lake in Hubbard County, Minnesota with a maximum depth of 54 feet (14-foot average). The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in Hubbard County, Little Mantrap Lake ranks #17 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-26. Methodology: how these readings are compared.
Little Mantrap Lake covers about 380 acres in Hubbard County. It has one public boat landing. The median ice-out date is April 21, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Little Mantrap Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Little Mantrap Lake is good for
From access and monitoring records, not editorial picks.
- Clear water17 ft of visibility
- Boat launch1 documented ramp
- Fishing13 species recorded
- Ice seasonIce-out around Apr 21
- Deep water54 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. Little Mantrap Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Little 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 Little Mantrap Lake
These are the measurements Minnesota PCA publishes for Little Mantrap 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 ft down. Phosphorus 8 µg/L. Chlorophyll-a 2.5 µg/L. TSI 37.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 17ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 8µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.5µg/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. | 37 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Little Mantrap Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Little Mantrap Lake typically sits around 58°F at the surface in October. Summer average is about 64°F. Usually warmest in Jul (about 65°F) and coldest in May (about 52°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (52°F) to its warmest (65°F).
Typical surface water temperature by month, from 127 field readings (2021–2025) via the EPA Water Quality Portal. See the full Little Mantrap Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Little Mantrap Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (118,032 cells/mL) on May 23, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on July 25, 2022 caught 2.67 walleye per gill net at Little Mantrap Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Little Mantrap Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. 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: 2022-07-25 (Standard Survey).
13 surveys on file · most recent 2022-07-25 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Bullhead | 16.43 | 5–13 in 2022-07-25 | 0.45 lb |
| Bluegill | 14.16 | 3–7 in 2022-07-25 | 0.15 lb |
| Green Sunfish | 12.76 | 3–5 in 2022-07-25 | 0.14 lb |
| Largemouth Bass | 8.95 | 5–17 in 2022-07-25 | 0.78 lb |
| Bluntnose Minnow | 7.08 |
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.
Yellow Bullhead
Bluegill
Green Sunfish
Largemouth Bass
From the 2022-07-25 survey
Little Mantrap Lake is located thirteen miles north of Park Rapids on the border of Becker and Hubbard County. Little Mantrap has a surface area of 381 acres and a maximum depth of 54 feet. A DNR owned public access is located on the south shore of the lake. Little Mantrap provides angling opportunities for Largemouth…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Little Mantrap Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Little MantrapFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Little Mantrap (1223)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Little MantrapFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Little MantrapPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
54 ft
Average depth
14 ft
Surface area
381 acres
Shoreline
9.2 mi
Littoral zone
52%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
5 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,512 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Little 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 Little Mantrap Lake
Compare lakeside cabins, hotels, and vacation rentals near Little 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 Little Mantrap 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 Little Mantrap Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Little Mantrap Lake
- → Little Mantrap Lake fishing: DNR survey catch rates, species & stocking
- → Little Mantrap Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Little Mantrap Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Little Mantrap Lake? (mercury & PFAS guide)
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Ice season
Typical ice-out
Apr 21
Earliest Mar 24, 2012 · Latest May 8, 2022
Typical ice-in
Nov 23
Earliest Nov 8, 2003 · Latest Dec 7, 1999
Most recent ice-out
Apr 6
2024
39 observations · Minnesota PCA ice records
EPA Impairment Status
Little Mantrap 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.
Source: EPA ATTAINS assessment unit MN29-0313-00 · Official waterbody report
Nearby Lakes in Hubbard County
Frequently asked questions about Little Mantrap Lake
Where is Little Mantrap Lake?
- Little 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 Little Mantrap Lake?
- Little Mantrap Lake in Hubbard County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 17 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 54 ft. Surface area: 380.95 acres.
Is Little Mantrap Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Little Mantrap 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 Little Mantrap Lake?
- Little Mantrap Lake typically sits around 58°F at the surface in October, from 127 EPA Water Quality Portal field readings (2021–2025). That is a typical value for the month, not a live reading.
How deep is Little Mantrap Lake?
- Little Mantrap Lake has a maximum depth of 54 feet and an average depth of 14 feet. The lake covers 380.95 acres.
What fish are in Little Mantrap Lake?
- Fish species found in Little Mantrap Lake include black bullhead, black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, yellow bullhead, yellow perch. Little Mantrap Lake is located in Hubbard County, Minnesota.
What did the DNR fisheries survey find at Little Mantrap Lake?
- Minnesota DNR's Standard Survey on July 25, 2022 caught 2.67 walleye per gill net at Little Mantrap Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Little Mantrap Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
When does Little Mantrap Lake thaw?
- Little Mantrap Lake typically has ice-out around Apr 21. Ice typically forms around Nov 23. The open water season is approximately 216 days.
Does Little Mantrap Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Little Mantrap Lake (clouds, ice, or an off-season gap). The most recent reading was high (118,032 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Little Mantrap Lake?
- Little Mantrap Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Little Mantrap Lake. Public access is listed as yes.
Can I fish at Little Mantrap Lake?
- Little Mantrap 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 Little Mantrap Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Hubbard County
Species activity outlook by water temperature and season
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Where to stay at Minnesota's top lakes, each with its readings
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Minnesota's cleanest lakes, ranked on agency measurements
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Where this data comes from
165 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
MNPCA165 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