I don't have a good sense of the full scope of what he's written -- the main body of his work seems to historical fic/non-fic and traditional stories -- but I know of at least four fantasy and/or horror titles: Wabi (YA quest fantasy), When the Chenoo Howls (a collection of horror stories from eight tribes), and Skeleton Man and its sequel.

Wabi is the only one of those I've read. I enjoyed it, and I'm usually meh about YA quest fantasy.