This thread (and the guy who started it) seem to know about the Rez end of the Black River.
viewtopic.php?f=1&t=4758&p=48406&hilit=black+river#p48406I try to stay off the Rez, so I know only about the NF end of it. I can tell you that a friend of mine, who is a fly fisherman and licensed guide, hiked upstream from Wildcat Crossing last summer and caught a whole bunch of fish, and later that week guided someone there, and they caught a whole bunch more.