Wisconsin Fish: Trout Stream Classifications

The DNR uses three categories to classify the different types of trout streams throughout the state. These are evident in Wisconsin Trout Streams [PUB-FH-806 2002, PDF 1,035KB], which provides a comprehensive list of trout streams throughout the state, and in Wisconsin Trout Stream Maps, a set of trout stream maps covering the majority of Wisconsin.

The classifications are as follows:

Class 1

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 4,136 miles of Class 1 trout streams in Wisconsin and they comprise 40% of Wisconsin's total trout stream mileage.

Class 2

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 average size.

There are 4,644 miles of Class 2 trout streams in Wisconsin and they comprise 45% of Wisconsin's total trout stream mileage.

Class 3

These waters are marginal trout habitat 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 1,591 miles of Class 3 trout streams in Wisconsin and they comprise 15% of Wisconsin's total trout stream mileage.