Cluster C included the Elm, Rush, Maple, Bois de Sioux, Mustinka, and Rabbit Rivers and the Wild Rice River in North Dakota. Cluster D included the Tongue, Middle, Snake, and Tamarac Rivers. Figure 7 . Cluster analysis of 27 streams in the Red River basin based upon the presence or absence of 76 naturally reproducing stream fish species. Figure 8 .
Axes are linear combinations of fish species.
A-D was determined using PCA scores from the first five axes for all streams. The four distinct clusters of streams produced by CA were used to place stream fish species into assemblages which represented common associations of fishes found in streams of each cluster. Figure 9 . Figure 10 . Figure 11 .