It’s a gruelling, tough track, taking competitors from Katoomba down into the Megalong Valley and finishing near the Jenolan Caves. 

Regardless of the extreme nature of the course, with altitude as low as 200 metres and as high as 1200 metres, the Ba-Thirst Runners see the event as a big social occasion. 

Twenty-two Ba-Thirst Runners will compete in the event, with Brian Smith and Stephen Jackson the most experienced competitors with 15 appearances at the marathon each. 

As well, Andrew Meenahan (14), Bill McKenna (12), Chris Grady (12), Trevor Bayliss (11) and Christopher Walsh (10) have all amassed double-digit appearances.

Bayliss said Bathurst numbers have seen a sharp increase in the past 13 years.

“My first marathon with my group was in 2005 and there was five of us. This year we've got 22 runners from Bathurst, from our Ba-Thirst Runners group,” he said.

“[The marathon is] renowned to be one of the toughest trail ultra marathons in Australia. It's got more and more popular each year, even if it's a tough one.

For Ba-Thirst Runners, they will make a four-day weekend out of the event, heading down to Katoomba on Friday to collect their bibs and have lunch.

“On Saturday, it's a 4.30am start for us, leaving for the start line,” Bayliss said.

“Then we've got a celebration afterwards and on Sunday, there's a barbecue at one of our runners house which we've done every year. It’s always good fun. 

“On Monday, we have a very funny golf day watching half a dozen runners who can't walk, play golf.”