ALARCON, HERNANDO DE, Spanish navigator of the i6th century, was sent by the viceroy of New Spain in 154o to give naval support to the expedition of Francisco Vasquez de Coronado in his search for the mythical seven cities of Mexico. The junction was never effected. Alarcon sailed up the Gulf of California, and determined with certainty that California was a peninsula, not an island. He surveyed the coast, ascended the Rio del Tizon or Rio de Buena Guia (Colorado) for 85 Spanish miles and planted a cross at the highest point he reached. Under the cross he buried a note afterwards found by Melchior Diaz. See Herrera, Decade VI. book ix. ch. is; vol. vi. fol. 212 of Madrid edition of 1 73o, and the report printed in Hakluyt's voyages.