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LakeQuality
D

Crane Lake

St. Louis County, MinnesotaLimited DataEutrophic

Crane Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 51, Crane Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake's 80 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 2,921 acres, Crane Lake is one of the larger lakes in St. Louis County, with 34.0 miles of shoreline supporting multiple distinct use patterns. Within the 187 graded lakes of St. Louis County, Crane Lake sits at rank 163, near the bottom of the county list.

An invasive species record — spiny waterflea — has been logged at Crane Lake; Minnesota PCA maintains the official infested-waters list. Muskie are on the species list at Crane Lake, alongside the lake's 12 other documented fish. A documented public access point at Crane Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 6 observed ice-outs, centered near Apr 27. 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.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Murky, only visible to about 6 ft. Trophic State Index: 51.

MetricValueGrade
Water Clarity (Secchi Depth)6 ftD
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)51Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth80 ft
Surface Area2.9K acres
Shoreline Length34 mi
Littoral Zone21%
Public AccessYes

Fish Species

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

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

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

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

Invasive Species

spiny waterflea

Water Quality Trend: Declining

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

MetricTrendChange/YearYears
Water Clarity Declining-0.219 m/yr5
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (6 observations).

Typical Ice-Out
Apr 27
EarliestLatest
Ice-Out2012-03-27 (2012)2014-05-14 (2014)

Most recent ice-out: 2019-04-24

Location

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County Ranking

Ranked #163 of 187 lakes in St. Louis County

Cleaner Lakes Within 30 Miles

Crane Lake holds Grade D. 2 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in St. Louis County

Eutrophic Lakes in Minnesota

DNR Fisheries Survey Summary

17 surveys on file from MN DNR Fisheries. Most recent: 2025-08-20 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Smallmouth Bass13.480.98 lb
Walleye7.820.8 lb
Tullibee (Cisco)6.000.6 lb
Yellow Perch5.500.14 lb
Northern Pike2.023.04 lb
White Sucker1.992.16 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.

Smallmouth Bass

51 fish · 319 in · 2021-05-31
950trophy 184681012141618

Walleye

223 fish · 723 in · 2021-05-31
39200trophy 24810121416182022

Tullibee (Cisco)

5 fish · 714 in · 2006-08-28
107891011121314

Yellow Perch

167 fish · 510 in · 2021-05-31
492505678910

From the 2025-08-20 survey

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Crane Lake on August 20th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Whitefish, the most sensitive coldwater species present in this lake (Cisco, also…

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 Crane Lake. 3 reports on file.

Data Sources

Water quality data from the EPA Water Quality Portal

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