Trout stream classifications
Wisconsin trout fishing
The DNR uses three categories to classify the different types of trout streams throughout Wisconsin. These are evident in Wisconsin Trout Stream Maps, which provide a comprehensive list of trout streams and a set of trout stream maps covering most of the state. Efforts have been made to list all trout streams in the State of Wisconsin, but it is recognized that this listing is not exhaustive.
The trout stream classifications are as follows:
High-quality trout waters that have sufficient natural reproduction to sustain populations of wild trout, at or near carry capacity. Consequently, streams in this category require no stocking of hatchery trout. These streams or stream sections are often small and may contain small or slow-growing trout, especially in the headwaters.
There are 5,365 miles of Class 1 trout streams in Wisconsin, comprising 40% of Wisconsin's total trout stream mileage.
Streams in this classification may have some natural reproduction, but not enough to utilize available food and space. Therefore, stocking is required to maintain a desirable sport fishery. These streams have good survival and carryover of adult trout, often producing some fish larger than the typical average-sized fish.
There are 6,120 miles of Class 2 trout streams in Wisconsin, comprising 46% of Wisconsin's total trout stream mileage.
These waters are marginal trout habitats with no natural reproduction occurring. They require annual stocking of trout to provide trout fishing. Generally, there is no carryover of trout from one year to the next.
There are 1,786 miles of Class 3 trout streams in Wisconsin, comprising 14% of Wisconsin's total trout stream mileage.