SUPERIOR TROUT STREAMS – How many are there?

It turns out that this is not an easy question to answer even with our GIS (Geographic Information Systems) and Internet wizardry.

A Minnesota trout stream is defined by State statute 97C.005, Minnesota Statutes 2006 and via DNR Rule 6264.0050 RESTRICTIONS ON DESIGNATED TROUT LAKES AND STREAMS. The DNR Rules chapter has a long list of streams arranged by county.

However, not all streams having trout have necessarily been added to the list, and there also can be multiple reaches for an individual stream. And it gets even more complicated since there are unnamed tributaries that are specified based on geographic location. From the DNR rules list for the Minnesota Lake Superior counties we counted the following numbers of "designated stream sections", but it is unclear how many of these actually drain into Lake Superior:

• Carlton County = 38
• Cook County = 84
• Lake County =101
• St. Louis County = 86

GIS estimates

• 2006 - Using data compiled in Coastal GIS and the Lake Superior Decision Support System, Jesse Schomberg at MN Sea Grant identified 720 perennial streams, 127 intermittent streams, and 1 ditch or canal that flow into Lake Superior which includes streams flowing from Islands on the lake as well. In the map (click to enlarge) the dark black line is the watershed boundary, the light blue lines are intermittent streams, and darker blue lines are perennial streams.
• 2007 – Using similar data sets but attempting to better estimate the actual number of streams, Gerry Sjerven at NRRI developed the table below that shows the Trout Streams and tributaries that flow into Lake Superior and directly into the St. Louis River. However, most streams were not named and so an intersect was done to add the minor watershed name to the streams (this is simplified GIS-Speak). The streams were then labeled first to the stream name (if available), then to the watershed name.

And of course this doesn’t include Ontario, the South Shore Wisconsin, or Michigan streams.