Sergeant Ian Kerrisk, of Alexandra, said police were told at 6.40pm that a group of riders, aged 20 to 74, had become trapped just below the summit at lunchtime and had spent several hours trying to walk 14km through snow to Danseys Pass Hotel.
Slideshow: Brass Monkey Rally 2010
The pass links North and Central Otago.
"Their decision to travel that road, past warning signs and locked gates, is foolish, to say the least, and could well have resulted in the loss of life.
"They not only put themselves at risk but caused others to have to risk the conditions to rescue them," Sgt Kerrisk said.
A search and rescue operation was launched, involving police, ambulance, SAR volunteers, the local 4WD club, a commercial grader and a local farmer with a large tractor.
A helicopter was requested but then stood down in the conditions, with searchers having to go in by road.
Sgt Kerrisk said police and SAR staff in 4WDs travelled up the road about 2km from the hotel, where they found a group of 20 riders.
Sgt Kerrisk said with deep snow further up the road, a large tractor and the grader were used to take searchers another 3km, where three riders were found walking.
Another three riders were found sheltering near the roadway 6km further on.
"Searchers continued up to ensure all persons were located and accounted for and found the snow near the summit shoulder-deep in places.
"The riders were all extremely cold and tired and very grateful to see the searchers.
They had been trying to walk through snow for some seven hours at that stage, in freezing conditions."
Sgt Kerrisk said they were nearing the end of their endurance.
He said they were taken back to the hotel to warm up, but none needed medical attention.
Danseys Pass Hotel manager Adrian Hood said a 74-year-old motorcyclist was "shattered" on his return to the hotel; his birthday celebrations being subsequently low-key.
All of the group, including some people from the North Island, had left by yesterday afternoon.
Mr Hood said more people were attempting to use the closed roads yesterday, but local people deterred them and threatened to call police if they ignored the closed signs.
Police are reviewing the Saturday night incident, but Sgt Kerrisk said charges were unlikely.
"They made a bad decision and they will have to answer to their families and peers for that.
"I hope this will be a learning curve for those involved. I'm sure a donation to the local Maniototo search and rescue organisation would be appreciated by the local community, but that is a matter for them."
