Long Lake
Beltrami County, MinnesotaMesotrophic
On the LakeGrade rubric, Long Lake pulls an A: clarity at 10.0 ft and 17 µg/L of phosphorus put it in the top bracket for Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
Mesotrophic conditions dominate at Long Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Long Lake is unusually deep for Minnesota at 83 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 202 acres, Long Lake fits the Minnesota median for monitored lakes, with 3.5 miles of shoreline. Long Lake ranks 33 of 86 in Beltrami County — solidly in the upper half of the local distribution.
No invasive species are currently listed at Long Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Long Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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 2021-09-27. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 10 ft. Phosphorus level: 17 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10 ft | B |
| Phosphorus | 17 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 83 ft |
| Surface Area | 201.57 acres |
| Shoreline Length | 3.5 mi |
| Littoral Zone | 21% |
| Public Access | Yes |
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.46 m/yr | 2 |
| Phosphorus | ↓ Declining | +2 µg/L/yr | 2 |
Location
County Ranking
Ranked #33 of 86 lakes in Beltrami County
Nearby Lakes in Beltrami County
More Minnesota Lake Rankings
State Parks Near Long Lake
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1986-06-25 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 57.00 | 0.16 lb |
| Hybrid Sunfish | 9.50 | 0.16 lb |
| Pumpkinseed | 8.50 | 0.2 lb |
| Northern Pike | 3.38 | 2.14 lb |
| Yellow Perch | 2.38 | 0.21 lb |
| White Sucker | 1.50 | 2 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
From the 1986-06-25 survey
HIGH NORTHERN PIKE POPULATION. BECAUSE OF SEVERE DROPOFF AROUND LAKE, RELIABLE NETTING IS DIFFICULT LOCAL FISHING REPORTS INDICATE A BETTER FISH POPU- LATION THAN REVEALED THAN REVEALED BY TEST NETTING
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lake. 3 reports on file.
- —Fisheries Lake Survey — BuzzleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Buzzle (1729)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — BuzzlePublic Water Access Sites · MN DNR LakeFinder
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2021-09-27
Monitoring stations: 1