Spirit Lake
Spirit Lake in Aitkin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11 ft visibility. Maximum depth: 46 ft. Surface area: 10.79 acres.
- Clarity
- 11 ft
- Typical in August
- 63°F
- Max depth
- 46 ft
- Area
- 11 acres
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Aitkin County
Why Spirit 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 Spirit 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.
Spirit Lake is a 11-acre lake in Aitkin County, Minnesota with a maximum depth of 46 feet (15-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.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-12. 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 Spirit Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11 ft. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Spirit Lake
Compare lakeside cabins, hotels, and vacation rentals near Spirit Lake in Aitkin 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 Spirit Lake
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Water Temperature
Spirit Lake typically sits around 63°F at the surface in August. Summer average is about 62°F. Usually warmest in Aug (about 63°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 261 field readings (2016–2025) via the EPA Water Quality Portal. See the full Spirit Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 46 ft |
| Average Depth | 15 ft |
| Surface Area | 11 acres |
| Shoreline Length | 0.6 mi |
| Littoral Zone | 56% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Spirit LakePublic
Fishing Spirit Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1986-06-04 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 0.50 | 0.38 lb |
| Northern Pike | 0.25 | 1 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1986-06-04 survey
The present fish population is made up of fish that have probably been stocked by anglers from other area lakes. In the 1958 survey the lake had a low population of northern pike and bluegill with a large population of yellow perch. Between 1914 and 1943 the lake had been stocked with walleye, bass, sunfish and…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Spirit Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Little TurtleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Little Turtle (0047)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.078 m/yr | 6 |
EPA Impairment Status
Spirit Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN01-0178-00 · Official waterbody report
Graded lakes near Spirit Lake
Spirit Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Aitkin County
Frequently asked questions about Spirit Lake
What is the water quality grade for Spirit Lake?
- Spirit Lake in Aitkin County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11 ft visibility. Maximum depth: 46 ft. Surface area: 10.79 acres.
Is Spirit Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Spirit 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 Spirit Lake?
- Spirit Lake typically sits around 63°F at the surface in August, from 261 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Spirit Lake?
- Spirit Lake has a maximum depth of 46 feet and an average depth of 15 feet. The lake covers 10.79 acres.
Are there boat ramps on Spirit Lake?
- Spirit Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Spirit Lake. Public access is listed as yes.
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Where this data comes from
84 measurements from 2 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
MNPCA84 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (2)
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory