[4][6] Approximately seventy per cent of the river's catchment lies within the boundaries of the Blue Mountains and Kanangra-Boyd national parks.

Endangered flora found include Hakea dohertyi, Trachymene saniculifolia and Diuris aequalis.

[6] The river's name appears to be derived from the local Aboriginal word gummung meaning "sore eyes", likely a term for the condition trachoma.

Surveyor H.C. White recorded the Kowmung name in 1833; however, the Gandangara people called the river Barnalay elsewhere along its course.

[2] In his attempt to cross the Blue Mountains in 1802, Francis Barrallier came to the river and followed it to Christys Creek before turning back due to a lack of supplies.