According to Pyle (1997):
"_O. f. idahoensis_ (br s BC-wID to sCA): Plumage averages paler
brownish; facial discs indistinctly defined and washed reddish
or grayish; streaking of the underparts dusky or reddish, and
narrow (narrower than the pale basal areas). Birds of interior
BC-ne.CA ("borealis") may average larger, darker and duller,
but differences are slight and obscured by individual variation."

It would appear that _idahoensis_ is the subspecies of eastern
Oregon and eastern Washington. The only other subspecies listed
is _O.f.frontalis_ which Pyle places in "sID-CO to AZ-wTX".



> Dennis K Rockwell wrote:
>

>
> I recently came into possession of a handful of early back issues of
> "The Condor" and have been having a lot of fun reading them. In Vol.
> XVIII, No. 6 (Nov. - Dec. 1916) I encountered the following report in
> the "FROM FIELD AND STUDY" section:
>
> The Dwarf Screech Owl in the State of Washington.--Unless it be
> for an occasional "sight record", I believe the Dwarf Screech Owl
> (Otus flammeolus idahoensis) has been seldom recorded in Washington.
> It gives me great pleasure, therefore, to report the capture of an
> adult female at Kiona, Benton County, Washington, by Mr. F. R. Decker
> of that place. An examination showed it to be beyond much doubt a
> breeding bird. The only possible nest sites in the vicinity were
> numerous holes made by Bank Swallows, etc., in a large sandy cliff, so
> it is possible that this bird may use something besides holes in trees
> as a place for raising its young. The specimen was taken on May 29,
> 1916, and is now in the collection of Mr. D. E. Brown, at Seattle,
> Washington.--J. H. Bowles, Tacoma, Washington.
>
> OK, right off the bat, I find no mention of the subspecies idahoensis
> in current literature describing the Flammulated Owl, so am I safe in
> assuming that this subspecies is no longer accepted ?
>

--
Mike Patterson
Astoria, OR
celata at pacifier.com

A child who becomes acquainted with the birds about him
hears every sound and puzzles out its meaning with a cleverness
that amazes those with ears who hear not.

-Neltje Blanchan

http://www.pacifier.com/~mpatters/bird/bird.html