Archibald Lake
Oconto County, WisconsinOligotrophic
Archibald Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oconto County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
Trophically, Archibald Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Archibald Lake is unusually deep for Wisconsin at 50 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. The lake's 392 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Archibald Lake sits at rank 34 of 66 in Oconto County, in the lower half of the local distribution.
Zebra mussels have been documented at Archibald Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at Archibald Lake, one of 4 fish species on record for the lake. Public access is available — the lake is on the Wisconsin DNR 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, Wisconsin DNR Surface Water, last sampled 2025-11-04. 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 55.4 ft down. Phosphorus level: 10.6 µg/L. Trophic State Index: 29.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 55.4 ft | A |
| Phosphorus | 10.6 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 29 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 50 ft |
| Surface Area | 392 acres |
| Public Access | Yes |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Archibald Lake (14-day solunar calendar)
→ Is it safe to eat fish from Archibald Lake? (mercury & PFAS guide)
→ Archibald Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.839 m/yr | 7 |
| Phosphorus | → Stable | -0.08 µg/L/yr | 6 |
Recreation & Access
Location
County Ranking
Ranked #34 of 66 lakes in Oconto County
Nearby Lakes in Oconto County
More Wisconsin Lake Rankings
State Parks Near Archibald Lake
Other Grade A Lakes in Wisconsin
Waukesha County · Clarity: 14.6 ft
Waukesha County · Clarity: 13.8 ft
Walworth County · Clarity: 19 ft
Washington County · Clarity: 12 ft
Kenosha County · Clarity: 10.1 ft
Washington County · Clarity: 12.5 ft
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1986. 20 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
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: 2025-11-04
Monitoring stations: 2