A flare caused a fire on the military ranges above Catterick Garrison last night.
Firefighters from Colburn, Richmond and Leyburn attended the incident.
The fire was reported at 8.38pm.
Crews arrived to find an area 30m by 30m alight.
North Yorkshire Fire and Rescue Service said the blaze was caused by a Shamooli — a flare attached to a small parachute which are used by the military to illuminate a large area.
The Colburn and Richmond crew were called initially with the Leyburn appliance attending to help with water supplies.