Heart Lake
Heart Lake in Clearwater County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 17 ft visibility. Maximum depth: 55 ft. Surface area: 224.49 acres.
- Clarity
- 17 ft
- Typical in August
- 76°F
- Max depth
- 55 ft
- Area
- 224 acres
- Trend
- ↑ Improving
- Public access
- No
Next lake in Clearwater County
Why Heart Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Heart Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Heart Lake is a 224-acre lake in Clearwater County, Minnesota with a maximum depth of 55 feet. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including bluegill, hybrid sunfish, and largemouth bass. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-11. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Heart Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Crystal clear, you can see 17 ft down. Trophic State Index: 36.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 36 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Heart Lake
Compare lakeside cabins, hotels, and vacation rentals near Heart Lake in Clearwater 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 Heart Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Heart Lake typically sits around 76°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 76°F) and coldest in Oct (about 58°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 36 field readings (2022–2025) via the EPA Water Quality Portal. See the full Heart Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 55 ft |
| Surface Area | 224 acres |
| Shoreline Length | 3.5 mi |
| Littoral Zone | 24% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Heart Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2013-07-01 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 27.28 | 0.19 lb |
| Largemouth Bass | 19.67 | 0.82 lb |
| Northern Pike | 6.14 | 2.39 lb |
| Rock Bass | 2.92 | 0.44 lb |
| Pumpkinseed | 2.41 | 0.13 lb |
| Black Crappie | 1.67 | 0.4 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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
Largemouth Bass
Northern Pike
Rock Bass
From the 2013-07-01 survey
Update 06/17/2014; There has been a change in public access status. The public access was leased by Clearwater County from the White Earth Reservation. That lease expired and has not been renewed. Heart Lake is a 206-acre lake with a maximum depth of 55 feet located 8 miles northwest of Itasca State Park in southern…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Heart Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HeartFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Heart (1692)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — HeartFish Stocking History · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.108 m/yr | 5 |
Graded lakes near Heart Lake
Heart Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Clearwater County
Frequently asked questions about Heart Lake
What is the water quality grade for Heart Lake?
- Heart Lake in Clearwater County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 17 ft visibility. Maximum depth: 55 ft. Surface area: 224.49 acres.
Is Heart Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Heart Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Heart Lake?
- Heart Lake typically sits around 76°F at the surface in August, from 36 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Heart Lake?
- Heart Lake has a maximum depth of 55 feet. The lake covers 224.49 acres.
What fish are in Heart Lake?
- Fish species found in Heart Lake include bluegill, hybrid sunfish, largemouth bass, rock bass, yellow perch. Heart Lake is located in Clearwater County, Minnesota.
Explore Heart Lake across LakeGrade
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Where this data comes from
46 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA46 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder