North Queensland jockey Chelsea Jokic has been given the chance to score the biggest win of her career on Mason's Chance in the $105,000 Country Cups Challenge at Doomben.

Saturday's final over 1600m is the culmination of a series of heats around Queensland and has attracted a field of 15.

While many in Saturday's field will be ridden by metropolitan jockeys, Mackay trainer Olivia Cairns has stuck with Jokic.

The rider is rapidly closing in on 300 career wins after stints in country NSW, the Sunshine Coast and now North Queensland.

She has shown tremendous resilience to recover from several falls which have resulted in a skull fracture, broken collar bone and injured knee in recent years.

Jokic recently followed in the footsteps of her father Stefan and brother Michael as a trainer when she took out a dual jockey-trainer licence.

She has ridden Mason's Chance in three of his past four starts for two wins and a second in North Queensland.

Justin Stanley, who is out injured, rode Mason's Chance when he won the Battle of The Bush at Doomben 18 months ago.

Mason's Chance is one of two runners for Cairns in Saturday's race along with Mustarrid who will be ridden by Michael Hellyer.

"Mason's Chance lost all form after his Battle of the Bush win but he is back in form now," Cairna said.

"He should get his chance from barrier five."

Mustarrid had stints with the Hayes partnership and Ben Currie before joining Cairns who has won five races with him.