The tanker was pulled upright and gas decanted into another vehicle
Peter Williams, 25, from the Darlington area, died in hospital after being thrown from the vehicle's cab at Wolsingham on Wednesday morning.
Residents of 23 homes which were evacuated have been allowed to return and an exclusion zone has been lifted.
A specialist recovery firm helped move the tanker amid fears it might explode.
The tanker made deliveries in rural areas to remote households and farms which use liquefied petroleum gas (LPG) as domestic fuel.
Before decanting the gas we had to right the vehicle, something which had to be done under great control
Chris Hockaday, County Durham and Darlington Fire and Rescue Service
The vehicle, a smaller version of a petrol tanker, was thought to have been carrying about 13,000 litres of LPG when it careered off the winding country road and crashed through a bridge.
Mr Williams was airlifted to Newcastle General Hospital where he was due to undergo surgery.
Following the evacuation of Wolsingham homes and a caravan park, the tanker was pulled upright and the gas decanted into another vehicle.
Chris Hockaday, from the County Durham and Darlington Fire and Rescue Service, said: "The decanting finished at about 10pm and the tanker was then dragged along the track by a tractor, where it was lifted onto another vehicle by the specialist recovery company.
The tanker smashed through a wall and plunged down an embankment
"It was then moved to a secure site for examination. The authorities left the scene at about midnight.
"Before decanting the gas we had to right the vehicle, something which had to be done under great control in an operation which took about two hours."
The Environment Agency had been alerted in case any diesel from the tanker leaked into the nearby River Wear.
The Weardale Railway, which runs steam trains on a five-mile stretch of restored track between Stanhope and Wolsingham Station, remains closed.
Road closed
Speaking on Thursday morning, Steve Raine, the railway's managing director said: "The tanker was moved late last night so we haven't yet been able to properly examine the track.
"However, the damage appears to be quite light and we're hoping we can get that fixed today.
"We'll work with the council to secure the collapsed wall and hopefully we'll be running trains tomorrow, but it's more likely to be Saturday."
The town's main road - the A689 - is unaffected by the crash but The Causeway route is likely to be closed until Saturday.
In May, a van containing gas cylinders exploded in Wolsingham's market place, killing the driver and causing widespread damage to homes and businesses.
The bridge where the accident happened. 
A gas tanker which crashed onto a preserved railway line in Wolsingham, County Durham in the north of England has been removed. Yesterday, the vehicle fell 70 feet from a road bridge onto the Weardale Railway below and left the driver with serious injuries from which he later died in hospital.

The driver of the Calor Gas vehicle has been named as Peter Williams who was 25 and from the Darlington area.

The tanker was said to be carrying 13,000 litres of liquefied petroleum gas at the time of the accident and nearby homes were evacuated due to fears the gas may leak from the vehicle. 

Chris Hockaday, from County Durham and Darlington Fire and Rescue Service, described the operation to empty the tanker of gas and remove it from the scene: "The decanting finished at about 10pm and the tanker was then dragged along the track by a tractor, where it was lifted onto another vehicle by the specialist recovery company. It was then moved to a secure site for examination. The authorities left the scene at about midnight. Before decanting the gas, we had to right the vehicle, something which had to be done under great control in an operation which took about two hours."

The Weardale Railway, which operates over a five mile section of restored track between Stanhope and Wolsingham, remains closed, but the company were optimistic about resuming services on the line.

Managing director of the Weardale Railway, Steve Raine, said "The tanker was moved late last night so we haven't yet been able to properly examine the track. However, the damage appears to be quite light, and we're hoping we can get that fixed today." He said that services were most likely to resume this Saturday.