Mons Lake
Todd County, Minnesota95 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Mons Lake. Here is what has been measured.
- 80 ft max depth
- Public access
- Limited data
Mons Lake in Todd County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.4 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.8 µg/L. Maximum depth: 80 ft. Surface area: 94.52 acres.
Minnesota DNR's Standard Survey on August 14, 2023 caught 0.50 walleye per trap net at Mons Lake. DNR survey details →
Mons Lake is a 95-acre lake in Todd County, Minnesota with a maximum depth of 80 feet. The lake supports 15 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-06-27. Methodology: how these readings are compared.
What Mons Lake is good for
From access and monitoring records, not editorial picks.
- Clear water15.4 ft of visibility
- Boat launch1 documented ramp
- Fishing15 species recorded
- Deep water80 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Mons 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 Mons Lake
These are the measurements Minnesota PCA publishes for Mons 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 15.4 ft down. Phosphorus 11 µg/L. Chlorophyll-a 2.8 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 15.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 2.8µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Mons Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Mons Lake typically sits around 65°F at the surface in September. Summer average is about 58°F. Usually warmest in Sep (about 65°F) and coldest in Jun (about 53°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (53°F) to its warmest (65°F).
Typical surface water temperature by month, from 173 field readings (2016–2025) via the EPA Water Quality Portal. See the full Mons Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 14, 2023 caught 0.50 walleye per trap net at Mons Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mons Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
14 surveys on file from MN DNR Fisheries. Most recent: 2024-08-15 (Targeted Survey).
14 surveys on file · most recent 2024-08-15 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Largemouth Bass | 29.60 | 6–13 in 2023-08-14 | 0.75 lb |
| Bluegill | 29.46 | 3–7 in 2023-08-14 | 0.13 lb |
| Tullibee (Cisco) | 10.25 | 8–15 in 2016-08-15 | 0.51 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.
Largemouth Bass
Bluegill
Tullibee (Cisco)
From the 2024-08-15 survey
Temperature and dissolved oxygen measurements were collected from the deepest basin in Mons Lake on August 15th, 2024, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. During…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mons Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MonsFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Mons (0898)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — MonsFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MonsPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
80 ft
Surface area
95 acres
Shoreline
1.8 mi
Littoral zone
22%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,178 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Mons 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 Mons Lake
Compare lakeside cabins, hotels, and vacation rentals near Mons Lake in Todd 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 Mons Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Mons Lake
Nearby Lakes in Todd County
Frequently asked questions about Mons Lake
Where is Mons Lake?
- Mons Lake is a lake in Todd County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Mons Lake?
- Mons Lake in Todd County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.4 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.8 µg/L. Maximum depth: 80 ft. Surface area: 94.52 acres.
Is Mons Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Mons Lake?
- Mons Lake typically sits around 65°F at the surface in September, from 173 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Mons Lake?
- Mons Lake has a maximum depth of 80 feet. The lake covers 94.52 acres.
What fish are in Mons Lake?
- Fish species found in Mons Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, pumpkinseed, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Mons Lake is located in Todd County, Minnesota.
What did the DNR fisheries survey find at Mons Lake?
- Minnesota DNR's Standard Survey on August 14, 2023 caught 0.50 walleye per trap net at Mons Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mons Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Mons Lake?
- Mons Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Mons Lake. Public access is listed as yes.
Can I fish at Mons Lake?
- Mons 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.
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Where this data comes from
4 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA4 samples · 2022
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2120 B ~ Color in Water by Visual Comparison
Monitoring station identifiers (1)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory