Spirit Lake
Aitkin County, MinnesotaLimited DataMesotrophic
Spirit Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth.
Mesotrophic conditions dominate at Spirit Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 46 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 11 acres, with 0.6 miles of shoreline and little volume to buffer nutrient inputs. Among the 53 graded lakes in Aitkin County, Spirit Lake sits at rank 17, above the county median.
No invasive species are currently listed at Spirit Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Spirit Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-08-31. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 11 ft. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11 ft | B |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 46 ft |
| Average Depth | 15 ft |
| Surface Area | 10.79 acres |
| Shoreline Length | 0.6 mi |
| Littoral Zone | 56% |
| Public Access | No |
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.03 m/yr | 5 |
Location
County Ranking
Ranked #17 of 53 lakes in Aitkin County
Nearby Lakes in Aitkin County
More Minnesota Lake Rankings
State Parks Near Spirit Lake
Other Grade B Lakes in Minnesota
Mesotrophic Lakes in Minnesota
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.
- —Fisheries Lake Survey — Little TurtleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Little Turtle (0047)Aquatic Plant Report · MN DNR LakeFinder
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
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-08-31
Monitoring stations: 2