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C

Leora Lake

St. Louis County, MinnesotaEutrophic

The LakeGrade rubric puts Leora Lake at a C: clarity at 7.0 ft, 46 µg/L of phosphorus, and a TSI of 54 signal an intermediate trophic state. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.

At a TSI of 54, Leora Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 35 ft puts Leora Lake in the middle of Minnesota's depth distribution. The lake's 263 acres and 2.8 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within St. Louis County's 187 graded lakes, Leora Lake ranks 115 — below the local median, though not at the bottom.

Leora Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The fishery includes walleye among the lake's 8 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. 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 2024-09-27. Grade methodology: LakeGrade methodology.

Reviewed by LakeQuality Editorial Team · Updated

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Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Moderate clarity, visible to about 7 ft. Phosphorus level: 46 µg/L. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)7 ftC
Phosphorus46 µg/LC
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth35 ft
Surface Area262.76 acres
Shoreline Length2.8 mi
Littoral Zone42%
Public AccessYes

Fish Species

black crappie,bluegill,largemouth bass,northern pike,pumpkinseed,walleye,white sucker,yellow perch

Click a species to see all Minnesota and Wisconsin lakes where it is found.

→ Best fishing times for Leora Lake (14-day solunar calendar)

→ Is it safe to eat fish from Leora Lake? (mercury & PFAS guide)

Leora Lake fishing regulations (limits, seasons, special rules)

Water Quality Trend: Stable

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.359 m/yr5
Phosphorus Improving-3.01 µg/L/yr5
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (7 observations).

Typical Ice-Out
Apr 21
Typical Ice-In
Nov 19

Estimated open water season: 212 days

EarliestLatest
Ice-Out2005-04-12 (2005)2020-04-24 (2020)
Ice-In2003-11-08 (2003)2004-12-05 (2004)

Most recent ice-out: 2020-04-24

Location

Loading map…

County Ranking

Ranked #115 of 187 lakes in St. Louis County

Cleaner Lakes Within 30 Miles

Leora Lake holds Grade C. 2 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in St. Louis County

Eutrophic Lakes in Minnesota

DNR Fisheries Survey Summary

6 surveys on file from MN DNR Fisheries. Most recent: 2021-08-09 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluntnose Minnow46.02
Bluegill13.880.19 lb
BNS13.17
Largemouth Bass9.551.11 lb
IOD3.74
Black Crappie3.370.36 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

44 fish · 38 in · 2021-08-09
1890345678

Largemouth Bass

53 fish · 520 in · 2021-08-09
840trophy 2068101214161820

Black Crappie

32 fish · 411 in · 2021-08-09
1580trophy 104567891011

From the 2021-08-09 survey

Leora Lake is a 263-acre lake with 110 (42%) littoral acres and a maximum depth of 35 feet. The lake is located east of Highway 53, near Cotton, MN. Leora Lake has a concrete, back in public access on the south side of the lake directly off of CR #49. Primary management species are Walleye and Largemouth Bass. Walleye…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Leora Lake. 4 reports on file.

EPA Impairment Status

Leora Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Mercury

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN69-0521-00 · 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

Ice data from Minnesota DNR Climate

Most recent sample: 2024-09-27

Monitoring stations: 1