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LakeQuality

Lost Lake

NR
Not yet rated
23 ft clear · Oligotrophic · 124 acres
Limited DataOligotrophic

Lost Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 23 ft visibility. Maximum depth: 44 ft. Surface area: 124.07 acres.

Clarity
23 ft
Typical in August
54°F
Max depth
44 ft
Area
124 acres
Trend
Improving
Public access
Yes

Next lake in St. Louis County

ACedar Island Lake3.8 ft clear · St. Louis CountyView →
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Why Lost Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Lost Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Lost Lake is a 124-acre lake in St. Louis County, Minnesota with a maximum depth of 44 feet. Overall water quality is improving over recent sampling years. The lake supports 8 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-16. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Ely

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Water quality measurements for Lost Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Crystal clear, you can see 23 ft down. Trophic State Index: 32.

MetricValueGrade
Water Clarity (Secchi Depth)23 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)32Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near Lost Lake

Compare lakeside cabins, hotels, and vacation rentals near Lost Lake in St. Louis County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Lost Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Lost Lake typically sits around 54°F at the surface in August. Summer average is about 59°F. Usually warmest in Jul (about 64°F) and coldest in Aug (about 54°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
Jul
64°
Aug
54°
Sep
54°
Oct
Nov
Dec

Typical surface water temperature by month, from 9 field readings (20102010) via the EPA Water Quality Portal.

Lake Details

CharacteristicValue
Maximum Depth44 ft
Surface Area124 acres
Shoreline Length3.4 mi
Littoral Zone39%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
5 sq mi
Elevation
1,342 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lost LakePublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Lost Lake

DNR Fisheries Survey Summary

3 surveys on file from MN DNR Fisheries. Most recent: 2014-06-23 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill16.040.14 lb
White Sucker2.932.17 lb
Northern Pike2.731.9 lb
Black Crappie2.710.22 lb
Yellow Perch2.530.1 lb
Pumpkinseed1.860.13 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

131 fish · 38 in · 2014-06-23
55280345678

White Sucker

24 fish · 1421 in · 2014-06-23
7401415161718192021

Northern Pike

43 fish · 1536 in · 2014-06-23
630trophy 361618202224262830323436

Black Crappie

11 fish · 510 in · 2014-06-23
530trophy 105678910

From the 2014-06-23 survey

Lost Lake is a 107 acre, ecological class 5 lake located off Co Rd 334 and 8 miles southeast of Eveleth. There is one public access with a gravel ramp in the southwest corner of the lake (parking is limited). Lost Lake has a maximum depth of 44 feet and clear water. Lost Lake was stratified on June 23, 2014 with a…

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 Lost Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.138 m/yr4
See year-by-year chart →

EPA Impairment Status

Lost 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 MN69-0556-00 · Official waterbody report

Graded lakes near Lost Lake

Lost Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in St. Louis County

Frequently asked questions about Lost Lake

What is the water quality grade for Lost Lake?

Lost Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 23 ft visibility. Maximum depth: 44 ft. Surface area: 124.07 acres.

Is Lost Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Lost Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

What is the water temperature of Lost Lake?

Lost Lake typically sits around 54°F at the surface in August, from 9 EPA Water Quality Portal field readings (2010–2010). That is a typical value for the month, not a live reading.

How deep is Lost Lake?

Lost Lake has a maximum depth of 44 feet. The lake covers 124.07 acres.

What fish are in Lost Lake?

Fish species found in Lost Lake include black bullhead, black crappie, bluegill, brown bullhead, hybrid sunfish, northern pike, pumpkinseed, white sucker. Lost Lake is located in St. Louis County, Minnesota.

Are there boat ramps on Lost Lake?

Lost Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lost Lake. Public access is listed as yes.

Where this data comes from

15 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA15 samples · 2020–2024

Analytical methods

  • Field measurement/observation, generic method
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory