Johnson Lake
Itasca County, Minnesota434 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Johnson Lake. Here is what has been measured.
- Oligotrophic
- 88 ft max depth
- Public access
Johnson Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.7 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.7 µg/L. Maximum depth: 88 ft. Surface area: 434.03 acres.
Minnesota DNR's Standard Survey on June 18, 2025 caught 0.56 walleye per gill net at Johnson Lake. DNR survey details →
Johnson Lake is a 434-acre cold, clear oligotrophic lake in Itasca County, Minnesota with a maximum depth of 88 feet. Phosphorus level is declining over recent sampling years. The lake supports 11 documented fish species including black crappie, bluegill, and hybrid sunfish. Public access is available with 1 public boat landing. Compared to the 71 other monitored lakes in Itasca County, Johnson Lake ranks #31 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-17. Methodology: how these readings are compared.
What Johnson Lake is good for
From access and monitoring records, not editorial picks.
- Clear water15.7 ft of visibility
- Boat launch1 documented ramp
- Fishing11 species recorded
- Ice seasonIce-out around Apr 22
- Deep water88 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 Johnson 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 Johnson Lake
These are the measurements Minnesota PCA publishes for Johnson 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 15.7 ft down. Phosphorus 9.5 µg/L. Chlorophyll-a 2.7 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 15.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 9.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.7µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Johnson Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Johnson Lake typically sits around 67°F at the surface in September. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in Sep (about 67°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (67°F) to its warmest (75°F).
Typical surface water temperature by month, from 19 field readings (2010–2021) via the EPA Water Quality Portal. See the full Johnson Lake water temperature breakdown →
Minnesota DNR's Standard Survey on June 18, 2025 caught 0.56 walleye per gill net at Johnson Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Johnson 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: 2025-06-18 (Standard Survey).
13 surveys on file · most recent 2025-06-18 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 8.35 | 3–7 in 2025-06-18 | 0.13 lb |
| Northern Pike | 3.97 | 13–29 in 2025-06-18 | 2 lb |
| Yellow Perch | 3.95 | 5–8 in 2025-06-18 | 0.15 lb |
| Bluntnose Minnow | 3.36 | ||
| Largemouth Bass | 3.15 | 4–18 in 2025-06-18 | 0.72 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.
Bluegill
Northern Pike
Yellow Perch
Largemouth Bass
From the 2025-06-18 survey
Johnson Lake is a clear, deep lake covering about 492 acres and located roughly thirteen miles north of Grand Rapids, Minnesota. The lake reaches a maximum depth of 88 feet and has excellent water clarity, with visibility of about 17 feet during the 2025 survey. Shallow nearshore habitat makes up about 146 acres, and…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Johnson Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — JohnsonFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Johnson (0614)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — JohnsonFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — JohnsonPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
88 ft
Surface area
434 acres
Shoreline
7.4 mi
Littoral zone
34%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,365 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Johnson 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 Johnson Lake
Compare lakeside cabins, hotels, and vacation rentals near Johnson Lake in Itasca 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 Johnson 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 Johnson 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 Johnson Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.91 µg/L/yr6 years
Chlorophyll-a
Improving-0.11 µg/L/yr6 years
Ice season
Typical ice-out
Apr 22
Earliest Apr 9, 1987 · Latest May 8, 1996
Typical ice-in
Nov 25
Earliest Nov 12, 1998 · Latest Dec 21, 1989
Most recent ice-out
May 6
2008
57 observations · Minnesota PCA ice records
Nearby Lakes in Itasca County
Frequently asked questions about Johnson Lake
Where is Johnson Lake?
- Johnson Lake is a lake in Itasca County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Johnson Lake?
- Johnson Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 15.7 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.7 µg/L. Maximum depth: 88 ft. Surface area: 434.03 acres.
Is Johnson 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 Johnson Lake?
- Johnson Lake typically sits around 67°F at the surface in September, from 19 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Johnson Lake?
- Johnson Lake has a maximum depth of 88 feet. The lake covers 434.03 acres.
What fish are in Johnson Lake?
- Fish species found in Johnson Lake include black crappie, bluegill, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Johnson Lake is located in Itasca County, Minnesota.
What did the DNR fisheries survey find at Johnson Lake?
- Minnesota DNR's Standard Survey on June 18, 2025 caught 0.56 walleye per gill net at Johnson Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Johnson 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 Johnson Lake thaw?
- Johnson Lake typically has ice-out around Apr 22. Ice typically forms around Nov 25. The open water season is approximately 217 days.
Are there boat ramps on Johnson Lake?
- Johnson Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Johnson Lake. Public access is listed as yes.
Can I fish at Johnson Lake?
- Johnson 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 Johnson 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 Itasca County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Lakes in the Rainy Lake Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Johnson Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Johnson Lake With Nearby Lakes
Where this data comes from
57 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
MNPCA57 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