Rainbow Trout
Invasive SpeciesFound in 5 lakes
Rainbow Trout appears on state infested-waters lists for 5 surface waters. Boaters and anglers moving gear in or out of those lakes carry a clean-drain-dry obligation under state law. 5 lakes — narrow enough that aggressive containment is still on the table. Most upper-Midwest invasives that established here did so quietly over a decade before anyone noticed, so a low number today is not a guarantee for tomorrow.
The presence of Rainbow Trout does not directly change a lake's LakeGrade rubric score — the grade measures the water itself, not the species inhabiting it. But invasive presence is a meaningful adjacent signal worth reading alongside the grade.
Lakes with Rainbow Trout
| Lake | County | State | Grade | Depth |
|---|---|---|---|---|
| Oswego Lake | Kosciusko | IN | B | - |
| Tippecanoe Lake | Kosciusko | IN | C | - |
| Mitchell Lake | Black Hawk | IA | D | - |
| James Lake | Kosciusko | IN | D | - |
| Meyers Lake | Black Hawk | IA | F | - |
Frequently Asked Questions
How many lakes have rainbow trout?
Rainbow Trout has been documented in 5 graded lakes: 3 in Indiana, 2 in Iowa.
Does rainbow trout affect water quality?
Invasive species can significantly affect lake ecosystems. They may alter nutrient cycling, displace native species, and change water clarity. Lakes with rainbow trout should be monitored for changes in water quality over time.
Source: EPA National Aquatic Resource Surveys, 2026.