Firefighters from Whitby were called out this morning to Blue Bank in the nearby village of Sleights.
They had received a report at 1.30am of a caravan fire on the notoriously steep stretch of the A169.
A North Yorkshire Fire Service spokesman said the fire had been started deliberately.
It involved two 5kg butane cylinders, one of which exploded.
The spokesman said: “The caravan, which was overturned following a road traffic collision on Friday, was totally destroyed by the fire.”
The crew used a hosereel jet, two breathing apparatus, a thermal imaging camera and lighting while putting out the blaze.
Blue Bank has a gradient of one in four and an escape lane of soft sand due to frequent road accidents.