Running through one of New Zealand's World Heritage areas, 225 runners will race from one end of the Routeburn Track to the other, traversing Mt Aspiring and Fiordland National Parks.
Multisport master Richard Ussher will be seeking his fifth Routeburn Classic overall title winning last year in 2hr 55min 30sec.
Christchurch's Jacob Roberts will be hoping to improve on his second place last year and also in contention is Queenstown multisporter Jim Hawkridge, who won the 2007 event, when Ussher did not compete.
Event director Evan McWhirter, of Good Times Events, said Paul Garvie, manager of Queenstown's Front Runner retail store, was a prospect, along with local runners Willy Roberts and Adrian Bailey.
"It's sure to be a tight thing between this group of runners," he said.
In the women's division, Elina Ussher will line up for the second time, hoping to match or improve on her record time.
"Other names to watch would be Queenstowner Jordan Davignon . . . last year's second place-getter Kristina Crane and Karen Muller, a running coach based in Christchurch who has been running competitively for 14 years in the UK and New Zealand," Mr McWhirter said.
However, track conditions on the day of the race could well impact on runners and results.
"In the past, we've had snow and ice on the track which challenges even the strongest competitors, so they've probably all got their fingers crossed for a fine, clear and dry day," he said.
Runners will start from the Divide, near Milford Sound, at 8am and finish near Glenorchy.
The Routeburn Classic is scheduled for Saturday, with a wet weather day set for Sunday.
