Crews were called from Tavistock, Yelverton, Princetown, Bere Alston, Crownhill, Greenbank, Moretonhampstead and beyond, with a total of 60 personnel involved.
A spokesperson for Devon Fire and Rescue Service said six crews were tackling the fire at the Princetown end and six at the Holne Ridge end to start with. The initial call from the Holne end had been at 9.20am, with a call from the Princetown area at 10.30am.
Originally, it was thought to be two separate incidents, but it was then discovered the fire had spread along the ridge from Holne.
A later call from a member of the public at Burrator was found to relate to the same incident. All firefighters were later moved to the Princetown end as the strong easterly wind was blowing the fire in that direction.
The fire was severe and the Environment Agency had been advised. Park rangers were assisting in fighting the fire. The police helicopter had been sent to the scene, but was called away when it was apparent there was nothing it could do. The fire was as visible on the ground as from the air, the spokesperson said.
?The situation has been compounded by the long period without rain. Unfortunately, with the recent weather comes added risks,? she said. The forecast was for high winds and no rain, so the crews were expected to be employed for some time.
The police helicopter was recalled to the scene at around 1.15pm to airlift an injured female firefighter to a waiting ambulance.
The helicopter then broadcast a warning to moor walkers to stay away from the scene of the blaze.
At first there was said to be no threat to farms or other properties, but as the Times went to press in the early afternoon park rangers became concerned that the fire was being blown towards Sheepstor. The cause of the fire was unknown.
l Two fire crews from Tavistock were called to a fire at a farm at Lamerton at 5.20pm on Easter Monday.
The fire was in a barn area, and was quickly brought under control, causing only minor damage. A calving simulator ? being a mock-up of the rear end of a cow used for training students ? was destroyed.
Station officer Tony Clarke said it appeared a short circuit had set fire to some rubbish. ?Luckily we caught it in time,? he said.
l There was what appeared to be a deliberate fire under a pile of logs near the viaduct at Magpie Bridge, near Horrabridge on April 20.
Station officer Clarke said it was a small fire in an awkward position, but had the potential for something more serious as it was in woodland. Fortunately, it was spotted by a member of the public and reported, he said.