Alpine Lake
Alpine Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12 ft visibility. Maximum depth: 65 ft. Surface area: 908.63 acres.
- Clarity
- 12 ft
- Max depth
- 65 ft
- Area
- 909 acres
- Trend
- ↓ Declining
- Public access
- No
Next lake in Cook County
Why Alpine 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 Alpine 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.
Alpine Lake is a 909-acre lake in Cook County, Minnesota with a maximum depth of 65 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-08. Grade methodology: LakeGrade methodology.
Watch Alpine Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Alpine Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 12 ft. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Alpine Lake
Compare lakeside cabins, hotels, and vacation rentals near Alpine Lake in Cook 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 Alpine 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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 65 ft |
| Surface Area | 909 acres |
| Shoreline Length | 23.9 mi |
| Littoral Zone | 44% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Alpine Lake
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2024-08-06 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 26.33 | 0.13 lb |
| LKW | 11.02 | 1.47 lb |
| Walleye | 4.25 | 1.95 lb |
| Northern Pike | 0.50 | 3.51 lb |
| White Sucker | 0.43 | 2.14 lb |
| Lake Trout | 0.17 | 5.9 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.
LKW
Walleye
Northern Pike
White Sucker
From the 2024-08-06 survey
Temperature and dissolved oxygen measurements were collected in the deepest basin in Alpine Lake, on August 6, 2024, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Lake Trout, the most sensitive coldwater species present in this lake (Lake Whitefish and Cisco,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Alpine Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — AlpineFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.17 m/yr | 5 |
EPA Impairment Status
Alpine Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN16-0759-00 · Official waterbody report
Nearby Lakes in Cook County
Frequently asked questions about Alpine Lake
What is the water quality grade for Alpine Lake?
- Alpine Lake in Cook County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12 ft visibility. Maximum depth: 65 ft. Surface area: 908.63 acres.
Is Alpine Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Alpine Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Alpine Lake?
- Alpine Lake has a maximum depth of 65 feet. The lake covers 908.63 acres.
Explore Alpine Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Cook County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Where this data comes from
7 measurements from 6 monitoring stations, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA7 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (6)
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