Rog Lake
Cook County, MinnesotaLimited DataOligotrophic
Rog Lake earns an A — every scored parameter (clarity) rates among the best monitored waters in Cook County.
Trophically, Rog Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake bottoms out at 40 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Rog Lake is small — 54 acres alongside 1.6 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Cook County's 128 graded waters, Rog Lake sits at rank 25, near the top of the local distribution.
No invasive species are currently listed at Rog Lake — the lake remains off the Minnesota infested-waters roster. The fishery is bass-led, with 4 documented species across the lake's records. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-07-13. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 26.2 ft down. Trophic State Index: 30.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 26.2 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 30 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 40 ft |
| Average Depth | 20.6 ft |
| Surface Area | 53.73 acres |
| Shoreline Length | 1.6 mi |
| Littoral Zone | 39% |
| Public Access | No |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Rog Lake (14-day solunar calendar)
→ Is it safe to eat fish from Rog Lake? (mercury & PFAS guide)
→ Rog Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +4.88 m/yr | 2 |
Location
County Ranking
Ranked #25 of 128 lakes in Cook County
Nearby Lakes in Cook County
More Minnesota Lake Rankings
Other Grade A Lakes in Minnesota
Oligotrophic Lakes in Minnesota
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2013-09-16 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 6.38 | 1.37 lb |
| Smallmouth Bass | 3.25 | 1.27 lb |
| Brook Trout | 2.74 | 1.7 lb |
| BUB | 1.27 | 0.29 lb |
| LNS | 1.00 | 3.46 lb |
| Walleye | 0.50 | 2.75 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
Smallmouth Bass
Brook Trout
BUB
From the 2013-09-16 survey
This was the first of two assessments scheduled in the 2006 lake management plan to determine whether a change in stocking strategy begun in 2009 resulted in improved brook trout abundance. It was hoped that stocking higher numbers of fingerlings would overcome losses to predation from smallmouth bass and possibly…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Rog Lake. 2 reports on file.
- —Fisheries Lake Survey — RogFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — RogFish Stocking History · MN DNR LakeFinder
EPA Impairment Status
Rog Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN16-0759-00 · Official waterbody report · Matched by proximity (2.07 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: 2022-07-13
Monitoring stations: 1