A large grass fire started in a quarry near Brockholes, say fire services.
Firefighters from Preston were called out to the incident at around 9pm on Sunday, April 29.
Crew Manager Chris Wales said: "The fire was quite large, measuring around 15 x 30m.
"Thankfully it had pretty much burnt itself out by the time we got there.
"The cause is under investigation but there are many things that could have started this including bbqs, cigarette ends or it could have been a deliberate fire.
"It's often difficult to pin down the cause.
"Please be careful and make sure you do not discard anything that could potentially cause a fire."
Nobody was injured in the incident and no buildings were damaged.
Crews spent just over an hour at the incident.