There were two recent deaths listed in the Lewiston Tribune (publication date 12/29/12) for Jess Dwane Knepper and his wife (I'm assuming) Geraldine F. Knepper. They were living in Caldwell, Idaho, at the time of their death; he on 12/25/12, and she on 12/13/12. Relyea Funeral Chapel in Caldwell, Idaho, handled the arrangements. You might find other family in that area.
Jess's age was 93; Geraldine was 96. Both are listed as being former Lewiston residents. I'm guessing this Jess may be a brother to the Allen that you're searching for.