Fremont Lake
Sherburne County, Minnesota493 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Fremont Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 8 ft max depth
- Public access
Fremont Lake in Sherburne County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 17.3 µg/L. Maximum depth: 8 ft. Surface area: 493 acres.
Minnesota DNR's Standard Survey on June 9, 2008 caught 7.00 northern pike per gill net at Fremont Lake. DNR survey details →
Fremont Lake is a 493-acre productive, nutrient-rich eutrophic lake in Sherburne County, Minnesota with a maximum depth of 8 feet (5-foot average). Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 17 other monitored lakes in Sherburne County, Fremont Lake ranks #11 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-08. Methodology: how these readings are compared.
What Fremont Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Ice seasonIce-out around Apr 2
Swimming conditions
Readings onlyRecreation use not supported
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. Fremont Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Fremont 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 Fremont Lake
These are the measurements Minnesota PCA publishes for Fremont Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3 ft of visibility. Phosphorus 40 µg/L. Chlorophyll-a 17.3 µg/L. TSI 59.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 40µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 17.3µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 59 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Fremont Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Fremont Lake typically sits around 64°F at the surface in September. Summer average is about 74°F. Usually warmest in Jul (about 79°F) and coldest in Feb (about 36°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (36°F) to its warmest (79°F).
Typical surface water temperature by month, from 69 field readings (2019–2025) via the EPA Water Quality Portal. See the full Fremont Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Fremont Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (33,113 cells/mL) on November 22, 2025.
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 June 9, 2008 caught 7.00 northern pike per gill net at Fremont Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Fremont Lake’s water-quality measurements separately, and the water-quality trend over 3 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2008-06-09 (Standard Survey).
4 surveys on file · most recent 2008-06-09 (Standard Survey)
18 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 92.53 | 1–8 in 2008-06-09 | 0.17 lb |
| Golden Shiner | 41.85 | 4–6 in 2008-06-09 | 0.07 lb |
| Hybrid Sunfish | 11.64 | 0.1 lb | |
| Bluegill | 10.75 | 1–7 in 2008-06-09 | 0.23 lb |
| Largemouth Bass | 9.27 | 13–15 in 2008-06-09 | 1.91 lb |
| Brown Bullhead | 8.77 | 7 in 2008-06-09 | 0.24 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.
Black Bullhead
Golden Shiner
Bluegill
Largemouth Bass
From the 2008-06-09 survey
Fremont Lake is a general development lake located in northeast Sherburne County, near Zimmerman. The lake is shallow, mostly 6-7 feet, with low to moderate water clarity (secchi depth 3.7 feet). Dissolved oxygen was adequate throughout the water column. These conditions are favorable for widespread aquatic plant…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Fremont Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — FremontFisheries Lake Survey · MN DNR LakeFinder
- —Public Water Access Sites — FremontPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
8 ft
Average depth
5.2 ft
Surface area
493 acres
Shoreline
5.3 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
8 sq mi
HydroLAKES / HydroSHEDS
Elevation
965 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lake FremontPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Fremont Lake
Compare lakeside cabins, hotels, and vacation rentals near Fremont Lake in Sherburne 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Fremont Lake are listed below.
Top-rated places to stay near Fremont 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 Fremont Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Fremont Lake
Water quality readings over time
3 seasons of samples on record (2020–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Improving-6.5 µg/L/yr2 years
Chlorophyll-a
Improving-3.48 µg/L/yr2 years
Ice season
Typical ice-out
Apr 2
Earliest Mar 7, 2017 · Latest Apr 30, 2018
Typical ice-in
Nov 30
Earliest Nov 24, 2007 · Latest Dec 9, 2017
Most recent ice-out
Mar 26
2026
16 observations · Minnesota PCA ice records
EPA Impairment Status
Fremont 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: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN71-0016-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Fremont Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Zimmerman WwtpZimmerman · 1.8 mi away · NPDES MN0042331Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Sherburne County
Frequently asked questions about Fremont Lake
Where is Fremont Lake?
- Fremont Lake is a lake in Sherburne County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Fremont Lake?
- Fremont Lake in Sherburne County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 17.3 µg/L. Maximum depth: 8 ft. Surface area: 493 acres.
Is Fremont Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Fremont Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Fremont Lake?
- Fremont Lake typically sits around 64°F at the surface in September, from 69 EPA Water Quality Portal field readings (2019–2025). That is a typical value for the month, not a live reading.
How deep is Fremont Lake?
- Fremont Lake has a maximum depth of 8 feet and an average depth of 5.2 feet. The lake covers 493 acres.
What did the DNR fisheries survey find at Fremont Lake?
- Minnesota DNR's Standard Survey on June 9, 2008 caught 7.00 northern pike per gill net at Fremont Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Fremont Lake’s water-quality measurements separately, and the water-quality trend over 3 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Fremont Lake thaw?
- Fremont Lake typically has ice-out around Apr 2. Ice typically forms around Nov 30. The open water season is approximately 242 days.
Does Fremont Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Fremont Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (33,113 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Fremont Lake?
- Fremont Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Fremont. Public access is listed as yes.
Can I fish at Fremont Lake?
- Fremont 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 Fremont 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 Sherburne County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Fremont Lake
Other Lakes in Minnesota
Eutrophic Lakes in Minnesota
Compare Fremont Lake With Nearby Lakes
Where this data comes from
79 measurements from 4 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
MNPCA79 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
Monitoring station identifiers (4)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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