Mushers battled a tough track at the weekend as they and their dogs bolted through the Naseby Forest well into the night.
Sixteen drivers raced teams through the forest on Saturday in the inaugural Southern Midnight Madness dryland sled-dog race.
It was the first time the South Island had hosted Midnight Madness, which is usually held in Taupo.
With its 80km, as well as 40km and 15km distances, it is believed to be the longest dryland sled-dog race in the world.
The event was run by the Otago Sled Dog Racing Association, which plans to host the event every second year to share the organising load.
Association president and co-organiser Nigel Voice said he thought in terms of dryland sled-dog events it was "the toughest long-distance race in New Zealand".
The event was "fantastic", he said.
"It was a bit warm for the dogs for the first hour or so, about 10degC, but then it got down to 3.8degC. Once it gets below about 4degC they really start going."
Mr Voice competed in the 40km race.
Co-organiser, and Mr Voice's wife, Rose was the only person to tackle the 80km distance, which consisted of two 40km loops and a one-hour rest period.
"It was a lot of hills, so it was extremely challenging. Some parts had river stones, other parts were grass, sand and there was quite a lot of mud in places. We had about four stream crossings."
Despite the event's name, Mrs Voice finished at 11.40pm, in a time of 9hr 40min, which included her rest period.
She was used to racing in the dark, she said.
"You're so busy concentrating on the dogs. Every now and then you think there could be a pig or something in the forest, but you think 'oh well' and just carry on.
"They all came back happy."
The popular Alaskan Malamute and Siberian Husky breeds were not the only dogs used, she said.
"There were Pointer crosses, Rottweiler crosses, Staffie crosses. One of my dogs is a little Kelpie-Collie cross, so he's not very big. A lot of it is what's between their ears, that mindset of wanting to work."
In the 40km race, competitor Cushla Fitzwater bested much larger teams with her two dogs to finish in a time of 3hr 37min.
The popular 15km event was won by Georgie Galloway with her two-dog team in 56 minutes.