George Arthur and Willis Spencer Brothers Vancouver 1900 S Information Please

I am trying to find information about two of my great uncles. Family say that George Arthur was blood brother to Chief Sitting Bull's son. I have photographs of Indian encampments and one of Chief Sitting Bull. George Arthur became a sharpshooter in Buffalo Bill's Circus. Both brothers trapped and spent time with native Americans, once being holed up in the snow for about six months in Alaska.

They came from Sheffield, Yorkshire, England.
They settled in the Vancouver/Victoria area of Canada. One became a highranking Mason and met up with King George on his boat "The Bluebottle".
I understand Willis spent his later years on a houseboat in Victoria.

Another relative Pat Spencer also lived in Vancouver and she visited us in the 1960's.

I have a small collection of pictures and other memorabilia to which I would like to give provenance.
All information very gratefully sought.