I have written a letter to the current enrollment officer at Spirit Lake and included with the letter the pedigree chart I received several years ago from the enrollment officer at the time. The chart did show, as Vicky stated above, that Sophia's father and mother were Sihatanka/Sihahaska and Ihanketowanwin. I asked in the letter if anyone knew WHICH Big Foot this was. Since the note typed on the chart also said that Sihatanka/Sihahaska had five wives, two of whom were Sisseton-Wahpeton and when he left Spirit Lake, those two returned to Spirit Lake. All very interesting but still leaves a question or two.
And here it is August 4, 2018 and I have not yet heard back from Spirit Lake. I also emailed another member of this forum who would have knowledge of Spirit Lake and it's history and still have not heard from him. It is difficult when many of us live hundreds of miles away from original places where ancestors lived. We cannot freely journey to these places. That is why I have appreciated so much those of you here on this site who have willingly taken your time and imparted what knowledge and/or records you have for those of us in "distant lands" so to speak. I know that at times there might be those who are reluctant to share what they know or, perhaps, are even reluctant to let go of information they have because what someone else finds might contradict it. I believe that our ancestral lines are sacred and that we should always endeavor to get it right whenever we can. True, we all will run into those "brick walls" where there is limited or even no records, be they written or word of mouth, that can be relied on. As a genealogist, and after 60 years of researching my own lines and years of researching my husbands, it is frustrating to get off on a line that really isn't ours. Not that I would even attempt to pick and chose who we descend from....I just want to get it right.