We studied movements and breeding success of resident Great Horned Owls (Bubo virginianus) at the Rocky Mountain Arsenal National Wildlife Refuge from 1994-1996. We captured adult owls prior to nest initiation and outfitted them with radio transmitters. Twelve, 5, and 11 pairs nested each year, respectively. Eleven nests successfully hatched and produced 24 owlets in 1994, 3 nests produced 6 owlets in 1995, and 10 nests produced 29 owlets in 1996. We documented three cases in which a single parent successfully fledged owlets. We recorded three cases of nest site reuse. Ninety-five percent adaptive kernel mean home range size did not differ between ages or sexes.