Sir Michael,
I can tell you that Ft. Vancouver has little in the way of Microfilm, though they can get it from Manitoba. I've tried to make sense of the Manitoba catalog system and it is rather vague, particularly when one tries to get specific information.
The folks at Vancouver tell me that the quality of the microfilm is rather poor. It is difficult to do primary research with them. Plus you need a reader.
I remember a rumor that Manitoba was/is converting their docs to digitized records, but I'm not holding my breath.
Oregon Historical Society here in Portland may have what you want, they used to have an online catalog. It is sporadically open to the public.
http://www.ohs.org/research/library/This link will get you to the online search...
http://librarycatalog.ohs.org/eosweb/opac/I have some Ft. Vancouver inventories from 1845-7 ish that may shed some light on what was around at that time, but I have no journals/recpts/logs of what may have gone to Boise.