This is a huge report, from 1994, so kind of dated. But I have read parts of it in the past to assist me in looking for the owls in Mt Hood NF. I have wondered if more effort has been done by the USFS in more recent years. http://www.sierraforestlegacy.org/Resources/Conservation/SierraNevadaWildlife/FlammulatedOwl/FO-Hayward.pdf Bob Archer pdx