Despite listing as a sensitive Species of Concern, the breeding status and biology of Flammulated Owls (Otus flammeolus  =  Psiloscops flammeolus) has been little studied in Montana. Compared to occurrence, breeding evidence is minimal. As of 2012, 664 records of Flammulated Owls existed in the Montana Natural Heritage Program database: 23 breeding and 641 occurrence records. From 2008 through 2012, we monitored 57 trees containing 131 cavities in 13 Flammulated Owl territories and documented 7 nests. We also documented the first tangible evidence of site fidelity by both sexes in Montana. Long-term, rigorous study of breeding biology and habitat is urgently needed to develop complete, accurate, and robust models for habitat management, and ultimately conservation of this migratory, forest-dwelling owl in Montana.