On 25 June 1983 I observed a Northern House Wren (Troglodytes aedon) feeding an undetermined number of nestlings in a nest of a Cliff Swallow (Hirundo pyrrhonota). The nest was located under the Bradley Road Bridge spanning the Salinas River in southern Monterey County, California, and was approximately 20–25 m above the river bank. Two additional swallow nests, one active, were immediately adjacent to the one used by the wren. Approximately 300 other active swallow nests were on the outer border of the bridge, separated from direct view of the wren nest by a lateral support beam.