Chaser Lake
Cook County, MinnesotaLimited DataHypereutrophic
Chaser Lake earns an F: phosphorus readings still being added and clarity at 1.0 ft signal heavy nutrient loading from the surrounding watershed.
The hypereutrophic status — TSI 77 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. The lake's 65 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 213 acres, Chaser Lake fits the Minnesota median for monitored lakes, with 6.6 miles of shoreline. Chaser Lake ranks 119 of 128 in Cook County — at the lower end of the locally monitored distribution.
No invasive species are currently listed at Chaser Lake — the lake remains off the Minnesota infested-waters roster. 4 fish species are on record, with panfish making up the recreational core. No formal public access is documented at Chaser Lake — most use is by shoreline residents and their guests. 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 2021-07-03. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1 ft of visibility. Trophic State Index: 77.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 77 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 65 ft |
| Average Depth | 24.4 ft |
| Surface Area | 213.13 acres |
| Shoreline Length | 6.6 mi |
| Littoral Zone | 40% |
| Public Access | No |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Chaser Lake (14-day solunar calendar)
→ Is it safe to eat fish from Chaser Lake? (mercury & PFAS guide)
→ Chaser Lake fishing regulations (limits, seasons, special rules)
Location
County Ranking
Ranked #119 of 128 lakes in Cook County
Nearby Lakes in Cook County
More Minnesota Lake Rankings
Other Grade F Lakes in Minnesota
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2025-08-04 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 7.66 | 1.43 lb |
| Lake Trout | 2.83 | 4.46 lb |
| Northern Pike | 2.56 | 2.99 lb |
| Green Sunfish | 1.00 | 0.08 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.
White Sucker
Lake Trout
Northern Pike
Green Sunfish
From the 2025-08-04 survey
Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Mesaba Lake on August 4th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake. During the summer,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Chaser Lake. 1 report on file.
- —Fisheries Lake Survey — MesabaFisheries Lake Survey · MN DNR LakeFinder
EPA Impairment Status
Chaser Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN16-0673-00 · Official waterbody report · Matched by proximity (1.56 km)
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: 2021-07-03
Monitoring stations: 1