The origin of the district's name is attributed to a Chinese entrepreneur of dried sea products known only by the name of Ma (馬, literally horses), who was one of the first settlers in the area.

The sea products, consisting of fish and squid, are dried on racks called rang by the local populace.

The district's topography consists of the South China Sea coast, peat swamps, hills and plains.

The sub-districts (Malay: mukim) of Rusila, Pulau Kerengga and Merchang lie on the coast with sandy plains gradually giving way to hills in the interior.

The district's population of 84,938 (2000 census) is 97.2% rural and predominantly Malays (97.2%) while the Chinese are the biggest ethnic minority (2.6%).