More than two years have passed since WA prospectors Raymond and Jennie Kehlet disappeared in the state's north.
An intensive search located Mr Kehlet's body in a mineshaft in Sandstone, but Mrs Kehlet has never been found.
A $250,000 reward for information has now been offered by Mr and Mrs Kehlet's family.
"It has been over two years since our parents Raymond and Jennie Kehlet went missing outside of Sandstone on a camping trip," said the family.
"Ray and Jennie were a compassionate, hardworking couple who were loved by their family, friends, and community. The last two years have seen our family caught in an agonising and exhausting limbo, desperate for answers and for closure.
"We extend our continued thanks and gratitude to the countless individuals who have given their time, expertice and dedication to helping our family.
"We are thankful that the police are still actively pursuing answers for our family, and hope that the offer of a reward may bring together the missing pieces of our family’s tragedy. We urge anyone with information to please come forward, and bring our family some peace."
Anyone with any information is asked to call Crime Stoppers on 1800 333 000 or make a report online at www.crimestopperswa.com.au.