Ponto Lake
Cass County, Minnesota388 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Ponto Lake. Here is what has been measured.
- Oligotrophic
- 60 ft max depth
- Public access
Ponto Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 19 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 60 ft. Surface area: 388.05 acres.
Minnesota DNR's Standard Survey on August 19, 2024 caught 6.33 walleye per gill net at Ponto Lake. Length samples in the latest survey that recorded them ran 12–24 inches. DNR survey details →
Ponto Lake is a 388-acre cold, clear oligotrophic lake in Cass County, Minnesota with a maximum depth of 60 feet. Overall water quality is declining over recent sampling years. The lake supports 16 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 103 other monitored lakes in Cass County, Ponto Lake ranks #42 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Methodology: how these readings are compared.
Ponto Lake covers about 390 acres in Cass County. It has one public boat landing. The median ice-out date is April 20, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Ponto Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Ponto Lake is good for
From access and monitoring records, not editorial picks.
- Clear water19 ft of visibility
- Boat launch1 documented ramp
- Fishing16 species recorded
- Ice seasonIce-out around Apr 20
- Deep water60 ft surveyed max depth
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. Check local advisories before you swim.
Whether Ponto 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 Ponto Lake
These are the measurements Minnesota PCA publishes for Ponto 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 19 ft down. Phosphorus 8 µg/L. Chlorophyll-a 2.1 µg/L. TSI 36.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 19ft | 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) | 2.1µg/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. | 36 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Ponto Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Ponto Lake typically sits around 71°F at the surface in September. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (76°F).
Typical surface water temperature by month, from 30 field readings (2011–2024) via the EPA Water Quality Portal. See the full Ponto Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 19, 2024 caught 6.33 walleye per gill net at Ponto Lake. Length samples in the latest survey that recorded them ran 12–24 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ponto Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2024-08-19 (Standard Survey).
12 surveys on file · most recent 2024-08-19 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 56.08 | 1–2 in 1996-08-20 | |
| Bluegill | 18.16 | 3–7 in 2024-08-19 | 0.13 lb |
| Yellow Perch | 6.93 | 6 in 2024-08-19 | 0.15 lb |
| Largemouth Bass | 5.49 | 5–17 in 2024-08-19 | 0.73 lb |
| Northern Pike | 5.10 | 15–29 in 2024-08-19 | 1.65 lb |
| Walleye | 4.29 | 12–24 in 2024-08-19 | 2.08 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.
Bluntnose Minnow
Bluegill
Yellow Perch
Largemouth Bass
From the 2024-08-19 survey
Ponto Lake is a 388-acre lake located northeast of Backus, Minnesota. A DNR owned public access is located on the southeast shore. Ponto Lake has 4.53 miles of shoreline, 102 littoral acres and a maximum depth of 60 feet. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota's lakes into 43…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ponto Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — PontoFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Ponto (1543)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — PontoFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — PontoPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
60 ft
Surface area
388 acres
Shoreline
4.5 mi
Littoral zone
26%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
7 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,332 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Ponto 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 Ponto Lake
Compare lakeside cabins, hotels, and vacation rentals near Ponto Lake in Cass 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 Ponto 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 Ponto Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Ponto Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.88 µg/L/yr3 years
Chlorophyll-a
Worsening+0.14 µg/L/yr3 years
Ice season
Typical ice-out
Apr 20
Earliest Apr 5, 2021 · Latest May 13, 2013
Typical ice-in
Nov 25
Earliest Nov 11, 1995 · Latest Dec 20, 2001
Most recent ice-out
Apr 5
2021
57 observations · Minnesota PCA ice records
Nearby Lakes in Cass County
Frequently asked questions about Ponto Lake
Where is Ponto Lake?
- Ponto Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Ponto Lake?
- Ponto Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 19 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 60 ft. Surface area: 388.05 acres.
Is Ponto 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 Ponto Lake?
- Ponto Lake typically sits around 71°F at the surface in September, from 30 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.
How deep is Ponto Lake?
- Ponto Lake has a maximum depth of 60 feet. The lake covers 388.05 acres.
What fish are in Ponto Lake?
- Fish species found in Ponto Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, burbot, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Ponto Lake is located in Cass County, Minnesota.
What did the DNR fisheries survey find at Ponto Lake?
- Minnesota DNR's Standard Survey on August 19, 2024 caught 6.33 walleye per gill net at Ponto Lake. Length samples in the latest survey that recorded them ran 12–24 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ponto Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Ponto Lake thaw?
- Ponto Lake typically has ice-out around Apr 20. Ice typically forms around Nov 25. The open water season is approximately 219 days.
Are there boat ramps on Ponto Lake?
- Ponto Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ponto Lake. Public access is listed as yes.
Can I fish at Ponto Lake?
- Ponto 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 Ponto 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 Cass County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Brainerd Lakes area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Lakes in the Pine River Watersheds (Brainerd Lakes), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Ponto Lake With Nearby Lakes
Where this data comes from
90 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA90 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 (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
Ice data from Minnesota DNR Climate