Skip to main content
LakeQuality
A

Little Fork Lake

Oneida County, WisconsinMesotrophic

Little Fork Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oneida County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Mesotrophic conditions dominate at Little Fork Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. The lake bottoms out at 34 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Little Fork Lake covers 336 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Little Fork Lake sits at rank 95 of 140 in Oneida County, in the lower half of the local distribution.

Little Fork Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery includes walleye alongside the lake's other 6 documented species — a notable draw for Wisconsin anglers. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-03-03. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 19.4 ft down. Phosphorus level: 21.2 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)19.4 ftA
Phosphorus21.2 µg/LB
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth34 ft
Surface Area336 acres

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for Little Fork Lake (14-day solunar calendar)

→ Is it safe to eat fish from Little Fork Lake? (mercury & PFAS guide)

Little Fork Lake fishing regulations (limits, seasons, special rules)

Invasive Species

Chinese Mystery SnailRusty Crayfish

Water Quality Trend: Declining

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.286 m/yr7
Phosphorus Stable+0.3 µg/L/yr2
See year-by-year chart →

Location

Loading map…

County Ranking

Ranked #95 of 140 lakes in Oneida County

Nearby Lakes in Oneida County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 2 stations on file (most recent sample 2025).

Fish Species (DNR-rated)

Musky(Common)Panfish(Common)Walleye(Common)Largemouth Bass(Present)Smallmouth Bass(Present)Northern Pike(Present)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-03-03

Monitoring stations: 1