The one thing we all probably should keep in mind is that during the specified times of 1871 through 1907 it wasn't in the best interest of people of Native American descent to admit to being such.
My grandmother, on my mother's side, has said to her husband when he would tell the growing children about being of this lineage and that not to tell the children those things because it wasn't a good idea to let it be known.
If you're not aware, though I'm sure you are, the natives were being expelled, expunged, and exterminated all in the name of the Manifest Destiny of the United States.A sad chapter in our country's history for sure, but what's done is done.
Now, my grandmother seemed to grow up with this mind set and more than likely than not obtained it from her parents, growing up during the above year spans you've pointed out to us.
So, why would Franklyn Bearse publish the material in 1933?Probably because he didn't care and wanted to make sure that any genealogy information he had obtained didn't become forgotten history.But I'm only theorizing as to the whys and why nots...
Just some food for thought and it's up to us to follow through and confirm what he's written.Don't give up hope, it's out there.