Long Lost Lake
Clearwater County, Minnesota539 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lost Lake. Here is what has been measured.
- Oligotrophic
- 63 ft max depth
- Public access
- Limited data
Long Lost Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 22 ft visibility. Phosphorus: 10.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 63 ft. Surface area: 539.04 acres.
Minnesota DNR's Standard Survey on July 29, 2024 caught 2.11 walleye per gill net at Long Lost Lake. DNR survey details →
Long Lost Lake is a 539-acre cold, clear oligotrophic lake in Clearwater County, Minnesota with a maximum depth of 63 feet (13-foot average). Overall water quality is declining over recent sampling years. The lake supports 11 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available. Compared to the 36 other monitored lakes in Clearwater County, Long Lost Lake ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-02. Methodology: how these readings are compared.
Long Lost Lake covers about 540 acres in Clearwater County. The median ice-out date is April 19, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Long Lost Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Long Lost Lake is good for
From access and monitoring records, not editorial picks.
- Clear water22 ft of visibility
- Fishing11 species recorded
- Ice seasonIce-out around Apr 19
- Deep water63 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Long Lost Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Long Lost Lake
These are the measurements Minnesota PCA publishes for Long Lost Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 22 ft down. Phosphorus 10.5 µg/L. Chlorophyll-a 2.4 µg/L. TSI 37.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 22ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.4µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 37 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Long Lost Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Long Lost Lake typically sits around 59°F at the surface in September. Summer average is about 69°F. Usually warmest in Aug (about 75°F) and coldest in Jun (about 59°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (59°F) to its warmest (75°F).
Typical surface water temperature by month, from 84 field readings (2011–2025) via the EPA Water Quality Portal. See the full Long Lost Lake water temperature breakdown →
Minnesota DNR's Standard Survey on July 29, 2024 caught 2.11 walleye per gill net at Long Lost Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lost Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2024-07-29 (Standard Survey).
8 surveys on file · most recent 2024-07-29 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluntnose Minnow | 40.40 | ||
| Bluegill | 16.83 | 3–8 in 2024-07-29 | 0.26 lb |
| Largemouth Bass | 9.96 | 5–16 in 2024-07-29 | 0.82 lb |
| Yellow Perch | 4.54 | 5–9 in 2024-07-29 | 0.2 lb |
| Northern Pike | 4.06 | 13–32 in 2024-07-29 | 1.37 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Largemouth Bass
Yellow Perch
Northern Pike
From the 2024-07-29 survey
Long Lost Lake is a 501-acre lake with a maximum depth of 63 feet located 8 miles south of the town of Zerkel in southern Clearwater County. Lake levels rose considerably since the early 1990s but have receded several feet in recent years, although the lake is still higher than historic levels. This has resulted in…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lost Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Long LostFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Long Lost (1338)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Long LostFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Long LostPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
63 ft
Average depth
12.5 ft
Surface area
539 acres
Shoreline
14.3 mi
Littoral zone
51%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
5 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,608 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Long Lost Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Lost Lake in Clearwater 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 Long Lost Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Long Lost Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Long Lost Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Ice season
Typical ice-out
Apr 19
Earliest Apr 2, 2010 · Latest May 14, 2013
Typical ice-in
Nov 29
Earliest Nov 8, 2003 · Latest Nov 30, 2006
Most recent ice-out
Apr 29
2020
18 observations · Minnesota PCA ice records
Nearby Lakes in Clearwater County
Frequently asked questions about Long Lost Lake
Where is Long Lost Lake?
- Long Lost Lake is a lake in Clearwater County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Long Lost Lake?
- Long Lost Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 22 ft visibility. Phosphorus: 10.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 63 ft. Surface area: 539.04 acres.
Is Long Lost Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Long Lost Lake?
- Long Lost Lake typically sits around 59°F at the surface in September, from 84 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Long Lost Lake?
- Long Lost Lake has a maximum depth of 63 feet and an average depth of 12.5 feet. The lake covers 539.04 acres.
What fish are in Long Lost Lake?
- Fish species found in Long Lost Lake include black crappie, bluegill, brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, smallmouth bass, walleye, white sucker, yellow perch. Long Lost Lake is located in Clearwater County, Minnesota.
What did the DNR fisheries survey find at Long Lost Lake?
- Minnesota DNR's Standard Survey on July 29, 2024 caught 2.11 walleye per gill net at Long Lost Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lost Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Long Lost Lake thaw?
- Long Lost Lake typically has ice-out around Apr 19. Ice typically forms around Nov 29. The open water season is approximately 224 days.
Can I fish at Long Lost Lake?
- Public access to Long Lost Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Long Lost Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Clearwater County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Long Lost Lake
Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Long Lost Lake With Nearby Lakes
Where this data comes from
118 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA72 samples · 2020–2025 - Minnesota Chippewa Tribe, Minnesota (White Earth Band) (Tribal)
WEARTH_WQX46 samples · 2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
Monitoring station identifiers (4)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate