The Master Surname Index (not online) (mostly burials in Alberta cemeteries) of the Alberta Genealogical Society lists 80 Powder names. Most are in the Ft McMurray, Ft Chipewyan, Wabaskaw, Slave Lake, Yellowknife areas.
You can ask the AGS Research Services Committee to send you all these names with the data.
For further research please contact the AGS Research Services Committee of the Edmonton Branch, http://abgensoc.ca/
The Edmonton Branchhttp://agsedm.edmonton.ab.ca