North Twin Lake
North Twin Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.4 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 59 ft. Surface area: 325.63 acres.
- Clarity
- 17.4 ft
- Typical in August
- 71°F
- Max depth
- 59 ft
- Area
- 326 acres
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 24
- Open water
- 218 days
Next lake in Beltrami County
North Twin Lake is a 326-acre cold, clear oligotrophic lake in Beltrami County, Minnesota with a maximum depth of 59 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 12 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing. Compared to the 84 other monitored lakes in Beltrami County, North Twin Lake ranks #21 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 17.4 ft down. Phosphorus level: 8 µg/L. Chlorophyll-a: 1.9 µg/L. Trophic State Index: 36.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17.4 ft | Not graded |
| Phosphorus | 8 µg/L | Good |
| Chlorophyll-a (Algae) | 1.9 µg/L | Good |
| Trophic State Index (TSI) | 36 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near North Twin Lake
Compare lakeside cabins, hotels, and vacation rentals near North Twin Lake in Beltrami 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.
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Water Temperature
North Twin Lake typically sits around 71°F at the surface in August. Summer average is about 72°F. Usually warmest in Jul (about 77°F) and coldest in May (about 68°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 17 field readings (2016–2021) via the EPA Water Quality Portal. See the full North Twin Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for North Twin Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (108,643 cells/mL) on April 25, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 59 ft |
| Surface Area | 326 acres |
| Shoreline Length | 3.8 mi |
| Littoral Zone | 42% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- North Twin LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing North Twin Lake
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2025-08-20 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluntnose Minnow | 33.40 | — |
| Bluegill | 16.51 | 0.18 lb |
| Largemouth Bass | 12.44 | 0.66 lb |
| Spottail Shiner | 7.50 | — |
| BNS | 5.88 | — |
| MMS | 5.60 | — |
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
Largemouth Bass
From the 2025-08-20 survey
Minnesota DNR Fisheries IBI program staff conducted an assessment of lakeshore habitat on North Twin Lake on August 20th, 2025, following the Score the Shore survey protocols. The assessment consisted of 30 survey sites evenly spaced 200 meters around the lake. Assessments were made in three habitat zones: Shoreline…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for North Twin Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — North TwinFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — North Twin (1757)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — North TwinFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — North TwinPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.016 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.44 µg/L/yr | 6 |
| Chlorophyll-a | → Stable | 0 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (11 observations).
Estimated open water season: 218 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2017-04-09 (2017) | 1996-05-09 (1996) |
| Ice-In | 2018-11-15 (2018) | 2004-12-03 (2004) |
Most recent ice-out: 2022-05-08
EPA Impairment Status
North Twin Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN04-0053-00 · Official waterbody report · Matched by proximity (1.18 km)
County Ranking
Ranked #21 of 85 lakes in Beltrami County
Nearby Lakes in Beltrami County
Frequently asked questions about North Twin Lake
What is the water quality grade for North Twin Lake?
- North Twin Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.4 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 59 ft. Surface area: 325.63 acres.
Is North Twin Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. North Twin Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 1.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of North Twin Lake?
- North Twin Lake typically sits around 71°F at the surface in August, from 17 EPA Water Quality Portal field readings (2016–2021). That is a typical value for the month, not a live reading.
How deep is North Twin Lake?
- North Twin Lake has a maximum depth of 59 feet. The lake covers 325.63 acres.
What fish are in North Twin Lake?
- Fish species found in North Twin Lake include black crappie, bluegill, brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow perch. North Twin Lake is located in Beltrami County, Minnesota.
When does North Twin Lake thaw?
- North Twin Lake typically has ice-out around Apr 24. Ice typically forms around Nov 28. The open water season is approximately 218 days.
Does North Twin Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for North Twin Lake (clouds, ice, or an off-season gap). The most recent reading was high (108,643 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on North Twin Lake?
- North Twin Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include North Twin Lake. Public access is listed as yes.
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Where this data comes from
78 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA78 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Ice data from Minnesota DNR Climate