The Mountains Have a Secret - Arthur Upfield

Two young women, hiking in the Grampian Mountains of western Australia vanish after staying a couple nights at a swank but isolated resort.  The immediate search and investigation turn up no sign of the women and no leads at all.  A few weeks later, a police officer investigating the disappearance is shot in his car......related to the disappearance or an isolated incident?  Bony, once again posing as a sheepman on vacation, begins to investigate.

Bony's strengths are nicely summarized by this glorious sentence:

His career as an investigator of violent crime had been unmarred by a single failure, and this was due much less to keen reasoning and keen observation, than to the inherited lust for the chase, bequeathed to him by a race of the greatest hunters the world has ever known, a race which has had to employ reason, patience, and unbreakable determination to gain sustenance in a country where food was ever hard to win.

This story includes several colorful characters and a nice mystery, though the resolution features some outlandish events inspired by World War II.