A MAJOR search is under way at Evans Head for missing mum Amber Christie.
Richmond Police District Leading Senior Constable Amanda Vidler said an aerial search is being conducted by police air wing, police rescue drones and surf life saving drones.
She said they had requested police divers to assist searching a number of places, including the river.
She said the search area was determined by "theories and high probability areas where a lost person may go".
Ms Christie is 162cm tall, with tawny brown, long hair and is athletic in build. She was last seen in the Oak and Park St areas in Evans Head on Sunday.