On 21 August 1990, Robert McKernan discovered a pair of Barn Swallows (Hirundo rustica) nesting near the city of Riverside. The observation was reported as the first breeding record in Riverside County in "recent history"(American Birds 44:1188).
Grinnell and Miller (1944) and Garrett and Dunn (1981) indicated that the breeding range of the Barn Swallow in southern California is restricted to coastal regions from Los Angeles County northward, and scattered localities in Orange, San Diego, and Imperial counties. No mention was made of breeding in Riverside and San Bernardinocounties.