Rusty Crayfish
Invasive SpeciesFound in 247 lakes
Rusty Crayfish is documented in 247 lakes across our dataset — 247 in Wisconsin. Each state's natural-resources agency maintains an official "infested waters" roster that triggers boat-launch decontamination protocols. A 247-lake footprint means Rusty Crayfish prevention has shifted from "stop the spread" to "manage the new normal." Watercraft-inspection programs at boat launches and shoreline-management practices on individual lakes are doing most of the active prevention work.
The presence of Rusty Crayfish does not directly change a lake's letter grade — the grade measures the water itself, not the species living in it. Invasive presence is still worth reading alongside the grade.
Lakes with Rusty Crayfish
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Green Lake | Green Lake | WI | A | 236 ft |
| Geneva Lake | Walworth | WI | A | 135 ft |
| Lac Courte Oreilles Lake | Sawyer | WI | A | 90 ft |
| Round Lake | Sawyer | WI | A | 74 ft |
| Sand Lake | Sawyer | WI | A | 50 ft |
| Grindstone Lake | Sawyer | WI | A | 60 ft |
| Lake St Croix | St. Croix | WI | B | 60 ft |
| Boulder Lake | Vilas | WI | B | 23 ft |
| Lake Noquebay | Marinette | WI | B | 51 ft |
| Spider Lake | Vilas | WI | B | 43 ft |
| Pickerel Lake | Forest | WI | B | 19 ft |
| Pickerel Lake | Oconto | WI | B | 10 ft |
| Beaver Dam Lake | Barron | WI | B | 106 ft |
| North Turtle Lake | Vilas | WI | B | 58 ft |
| Silver Lake | Forest | WI | B | 20 ft |
| Plum Lake | Vilas | WI | B | 57 ft |
| Whitefish Lake | Oneida | WI | B | 33 ft |
| Round Lake | Oneida | WI | B | 15 ft |
| Bass Lake | Oneida | WI | B | 20 ft |
| Bass Lake | Oconto | WI | B | 40 ft |
| Clear Lake | Rusk | WI | B | 74 ft |
| Pioneer Lake | Vilas | WI | B | 27 ft |
| Little Spider Lake | Vilas | WI | B | 23 ft |
| Bone Lake | Polk | WI | B | 43 ft |
| Lake Lucerne | Forest | WI | B | 73 ft |
| Bear Lake | Forest | WI | B | 20 ft |
| Bear Lake | Oneida | WI | B | 20 ft |
| Bear Lake | Waupaca | WI | B | 62 ft |
| Long Lake | Bayfield | WI | B | 28 ft |
| Long Lake | Chippewa | WI | B | 101 ft |
| Lake Metonga | Forest | WI | B | 79 ft |
| Birch Lake | Vilas | WI | B | 45 ft |
| Pike Lake | Washington | WI | B | 45 ft |
| Anderson Lake | Vilas | WI | B | 63 ft |
| Anderson Lake | Oconto | WI | B | 40 ft |
| Red Cedar Lake | Barron | WI | B | 53 ft |
| Pewaukee Lake | Waukesha | WI | B | 45 ft |
| High Lake | Vilas | WI | B | 36 ft |
| Butternut Lake | Forest | WI | B | 42 ft |
| Paya Lake | Oconto | WI | B | 40 ft |
| Island Lake | Rusk | WI | B | 54 ft |
| Island Lake | Oneida | WI | B | 26 ft |
| Lake Emily | Portage | WI | B | 35 ft |
| Big Lake | Vilas | WI | B | 30 ft |
| Papoose Lake | Vilas | WI | B | 65 ft |
| Kentuck Lake | Vilas | WI | B | 40 ft |
| Lower Eau Claire Lake | Bayfield | WI | B | 41 ft |
| Deer Lake | Polk | WI | B | 46 ft |
| Boot Lake | Oconto | WI | B | 38 ft |
| Little Crooked Lake | Vilas | WI | B | 30 ft |
Showing 50 of 247 infested lakes.
Frequently Asked Questions
How many lakes have rusty crayfish?
Rusty Crayfish has been documented in 247 graded lakes: 247 in Wisconsin.
Does rusty crayfish affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with rusty crayfish should be monitored for changes in water quality over time.
Invasives Found With Rusty Crayfish
Co-occurs in 154 lakes · 494 total
Co-occurs in 117 lakes · 362 total
Co-occurs in 96 lakes · 420 total
Co-occurs in 85 lakes · 275 total
Co-occurs in 42 lakes · 667 total
Co-occurs in 9 lakes · 57 total
More on invasive species and lake health
Zebra mussel counts from the lakes LakeQuality grades, the counties that show up most often, and the Clean, Drain, Dry rules that still matter.
How lakes are graded A–F on nutrients and algae using EPA ecoregion condition classes, what each letter means in the water, and why an A is not a clearance.
Before you buy lakefront, check the water: clarity trend, nutrient impairment, algae advisories, invasive species, and depth — a data-backed checklist.
Source: EPA National Aquatic Resource Surveys, 2026.