Lake Montello
Lake Montello in Marquette County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.1 ft visibility. Maximum depth: 17 ft. Surface area: 341 acres.
Wisconsin DNR lists Panfish as common on Lake Montello. DNR survey details →
- Clarity
- 6.1 ft
- Max depth
- 17 ft
- Area
- 341 acres
- Trend
- ↓ Declining
- Public access
- Yes
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Why Lake Montello has no grade
We grade a lake only when the monitoring record supports a letter: 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 Lake Montello, 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 WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Lake Montello is a 341-acre lake in Marquette County, Wisconsin with a maximum depth of 17 feet. Overall water quality is declining over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 5 public boat landings.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2021-10-23. Grade methodology: LakeQuality methodology.
Watch Lake Montello water quality
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Lake Montello
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 6.1 ft. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.1 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Lake Montello
Compare lakeside cabins, hotels, and vacation rentals near Lake Montello in Marquette County, Wisconsin — 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 Lake Montello
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as common on Lake Montello.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Lake Montello — official chemistry is on file, not a letter, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 5 stations on file (most recent sample 2021).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Lake Montello covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2024Montello Lake spring shocking survey, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 17 ft |
| Surface Area | 341 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Dam SitePublic
- Moon LakePublic
- Kilby LakePublic
- Lake StreetPublic
- MontelloPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Lake Montello
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -1.032 m/yr | 2 |
Reservoir Info (USACE NID)
Lake Montello is a man-made reservoir impounded by the Buffalo Lake Dam (completed 1922) on the FOX; gravity-type dam, 13 ft tall and 2,800 ft long.
- Surface area
- 2,210 ac
- Normal storage
- 10,000 ac-ft
- Max storage
- 19,000 ac-ft
- Drainage area
- 398 sq mi
- Hazard class
- Low
- Owner
- Wisconsin Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID WI01015 · Operator website
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lake Montello under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Montello Wastewater Treatment FacilityMontello · 1.2 mi away · NPDES WI0024813Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Graded lakes near Lake Montello
Lake Montello has no grade, but these lakes within a short drive do.
Nearby Lakes in Marquette County
Frequently asked questions about Lake Montello
Where is Lake Montello?
- Lake Montello is a lake in Marquette County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Lake Montello?
- Lake Montello in Marquette County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.1 ft visibility. Maximum depth: 17 ft. Surface area: 341 acres.
Is Lake Montello safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Montello 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 Lake Montello?
- Lake Montello has a maximum depth of 17 feet. The lake covers 341 acres.
What fish are in Lake Montello?
- Fish species found in Lake Montello include Panfish, Largemouth Bass, Northern Pike. Lake Montello is located in Marquette County, Wisconsin.
What did the DNR fisheries survey find at Lake Montello?
- Wisconsin DNR lists Panfish as common on Lake Montello. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Lake Montello — official chemistry is on file, not a letter, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Lake Montello?
- Lake Montello has 5 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Dam Site, Moon Lake, Kilby Lake, Lake Street, among others. Public access is listed as yes.
Explore Lake Montello across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Marquette County
Species activity outlook by water temperature and season
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Wisconsin's cleanest and most-polluted lakes, ranked
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Eutrophic Lakes in Wisconsin
Where this data comes from
5 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX5 samples · 2021
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory