The name honours Lt William Crossman of the Royal Engineers, who arrived in Fremantle as a second lieutenant stationed in Perth in 1852, but was responsible for works in the Albany district and for roads in the area. In 1853, in company with surveyor A.C. Gregory, he examined and reported on various routes between Perth and Albany, and recommended that the then-current routes via York or Bunbury be replaced by a straight line between Kelmscott (now a Perth suburb near Armadale) and Albany. After serving as colonial magistrate, he returned to England in 1856 and later was promoted to captain and served as a British Member of Parliament for Portsmouth. The Crossman River, a 42 kilometres (26 mi) tributary of the Hotham River, was most likely named by A.C. Gregory in 1853.
Crossman Wildflower Reserve, a year-round sanctuary for flora and fauna and home to a wide range of native orchids, including the rattle beaks, which only flower after fire.and Woolpack Lavender Farm, which opened in January 2003 and showcases lavender varieties.