Upper Maple Lake
Upper Maple Lake in Wright County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.2 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 3.6 µg/L. Maximum depth: 76 ft. Surface area: 632.6 acres.
- Clarity
- 17.2 ft
- Typical in August
- 76°F
- Max depth
- 76 ft
- Area
- 633 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 16
Next lake in Wright County
Upper Maple Lake is a 633-acre mesotrophic lake in Wright County, Minnesota with a maximum depth of 76 feet (19-foot average). Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 50 other monitored lakes in Wright County, Upper Maple Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-17. 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 17.2 ft down. Phosphorus level: 17 µg/L. Chlorophyll-a: 3.6 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 17.2 ft | Not graded |
| Phosphorus | 17 µg/L | Good |
| Chlorophyll-a (Algae) | 3.6 µg/L | Good |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Upper Maple Lake
Compare lakeside cabins, hotels, and vacation rentals near Upper Maple Lake in Wright 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
Upper Maple Lake typically sits around 76°F at the surface in August. Summer average is about 75°F. Usually warmest in Jul (about 78°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 76 field readings (2010–2023) via the EPA Water Quality Portal. See the full Upper Maple Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Upper Maple Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (108,643 cells/mL) on May 9, 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 | 76 ft |
| Average Depth | 18.8 ft |
| Surface Area | 633 acres |
| Shoreline Length | 7.2 mi |
| Littoral Zone | 63% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Maple Lake (West)Public
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Upper Maple Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
11 surveys on file from MN DNR Fisheries. Most recent: 2025-07-14 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 39.09 | 0.16 lb |
| SFS | 15.61 | — |
| Largemouth Bass | 14.32 | 1 lb |
| Yellow Bass | 9.58 | 0.56 lb |
| Bluntnose Minnow | 6.64 | — |
| BCS | 5.66 | — |
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
Yellow Bass
BCS
From the 2025-07-14 survey
Maple Lake is a 777-acre lake located just east of the City of Maple Lake in Wright County. It is a popular destination and offers a variety of angling opportunities (Walleye, Northern Pike, bass, and panfish). The lake has a maximum depth of 76 feet and water quality is good. There are two public accesses on the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Upper Maple Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Upper MapleFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Upper MapleFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Upper MaplePublic 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 | ↓ Declining | -0.292 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.84 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -0.61 µg/L/yr | 5 |
Ice Season
Historical ice data from Minnesota DNR (5 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2020-04-05 (2020) | 2019-04-20 (2019) |
| Ice-In | 2018-11-20 (2018) | 2015-12-19 (2015) |
Most recent ice-out: 2022-04-16
EPA Impairment Status
Upper Maple 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 MN86-0134-01 · Official waterbody report
County Ranking
Ranked #4 of 51 lakes in Wright County
Nearby Lakes in Wright County
Frequently asked questions about Upper Maple Lake
What is the water quality grade for Upper Maple Lake?
- Upper Maple Lake in Wright County, Minnesota has a water quality grade of A (Excellent). Water clarity: 17.2 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 3.6 µg/L. Maximum depth: 76 ft. Surface area: 632.6 acres.
Is Upper Maple Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Upper Maple Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.6 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Upper Maple Lake?
- Upper Maple Lake typically sits around 76°F at the surface in August, from 76 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Upper Maple Lake?
- Upper Maple Lake has a maximum depth of 76 feet and an average depth of 18.8 feet. The lake covers 632.6 acres.
What fish are in Upper Maple Lake?
- Fish species found in Upper Maple Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Upper Maple Lake is located in Wright County, Minnesota.
When does Upper Maple Lake thaw?
- Upper Maple Lake typically has ice-out around Apr 16.
Does Upper Maple Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Upper Maple 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 Upper Maple Lake?
- Upper Maple Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Maple Lake (West). Public access is listed as yes.
Explore Upper Maple Lake across LakeGrade
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Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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Where this data comes from
180 measurements from 2 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
MNPCA180 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 (2)
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