The riders were stranded upright aboard the new Superman Ultimate Flight roller coaster at Six Flags Discovery Kingdom in Vallejo for less than 90 minutes Sunday afternoon before the roller coaster was restarted.
Park spokeswoman Nancy Chan told The Associated Press that crews found no mechanical problems with the new ride or track.
They are still investigating what caused the coaster to stall and plan to run its cars later Monday.
Vallejo firefighters arrived at the park around 3 p.m. after the coaster stalled. A theme park crane equipped with a large personnel bucket was prepared to reach the riders.
Two firefighters and a park mechanic were lifted up in the bucket and gave water bottles to the riders, according to the Vallejo Times-Herald.
A park mechanic eventually restarted the ride, which then went backward and lowered the riders safely to the ground.
Fire Battalion Chief Ray Jackson said firefighters were prepared to take riders down in the bucket if the coaster couldn't be restarted.
None of the stranded riders was injured, Jackson said.
The ride opened June 30. It holds two cars with six riders each and can travel up to 62 mph.