On 1 July 1977 an adult and two downy young Flammulated Owls (Otus flammeolus) were discovered in an artificial nest box in southeastern Utah. The nest box was 1 of 12 placed at various heights and exposures in selected Ponderosa Pines (Pinus ponderosa) to determine if Abert Squirrels (Sciurus aberti) would use artificially constructed nest sites. The boxes measured 30.5 cm × 30.5 cm × 50.8 cm, were constructed of pine, had a hinged, sloping roof and a 6.4 cm diameter entrance hole positioned 6.4 cm from the top of the box (Pederson et al., Habitat requirements of the Abert Squirrel on the Monticello District, Manti-LaSal National Forest of Utah, Utah Div. of Wildl. Res. Publ. No. 76-9, 108 p.). The occupied nest box was placed against the trunk of the Ponderosa at a height of 12.5 m and faced northeast. The tree, one of a clump of three left after the harvest, had a height of 19.8 m and a diameter at breast height of 35.6 cm. Examination of this box in 1974-1977 showed use by Abert Squirrels, Red Squirrels (Tamiasciurus hudsonicus) and Common Flickers (Colaptes auratus). When the box was examined again on 17 October 1977, no evidence of the adult or young was found. Successful fledging of the young is assumed.