hey skookum1 
 Yah, I saw the article was flagged for improvement so I added a few things.  It obvioulsy will need to be cleaned up and citations added, but I am a bit too busy at the moment.  Will get to it though. 

 I am not familiar with your Teit reference at the moment.  Part of the confusion was that Boas/Teit classified the Sinixt within the larger "Okanagan", but then subdivided the Okanagan proper to sometimes include a "Lake" division, as opposed to the "Lakes" which is always a reference to the sinixt.  My suspicion is that he was referring to the former, although I am definately interested. 

 I will also add a language stub.  I recall reading it was similar to colville, but more 'drawn out'.   

 Teit (and others) describe the late pre-contact war with the Ktunaxa, in which the Sinixt were eventually able to stop the aggressors by a final large-scale raid on the Southern Ktunaxa. 

 There is, however, quite a lot of evidence that there was significant regional conflict at some time prior to the smallpox.  Many pithouse villages seem to have been abandoned in the 1400s.  I suspect that there was major Athabaskan/Salish/Ktunaxa conflict far beyond the basic Nicola/chilcotin enigma.  Let's not forget that the Apache/navajo etc. had only just arrived in the Southern plains when the Spanish got there in the 1500s (The Apache were reeking havoc at the time amongst the non-nomadic peoples who were indigenous to the area.).  There are differing theories among archeologists about whether it was strictly a plains migration or 'inter-montaine'.