A cewar ƙamus, Hamadar Simpson wani babban yanki ne, wanda ba kowa a cikin hamada a tsakiyar Ostiraliya, yana mamaye wani yanki mai faɗi fiye da murabba'in mil 68,000 (kimanin murabba'in kilomita 176,500). Yana da alaƙa da dunƙulen yashi ja, ƙananan ciyayi, da matsanancin yanayin zafi, tare da dunƙulen yashi mafi girma a duniya wanda ya kai ƙafa 1,000 (mita 305) tsayi. Hamadar Simpson gida ce ga flora da fauna iri-iri na musamman, gami da nau'ikan tsuntsaye, dabbobi masu rarrafe, da na marsupials.