Around 1,970 acres of moorland at Anglezarke have been destroyed in the raging fires, including 30 acres of woodland.
The scale of the devastation is starting to emerge and, so far, 70,000 trees have perished.
And both ground- and tree-nesting breeding birds have been seriously affected.
Across the county, there have been fires on moorland in Belmont, at a peat bog near Ormskirk and another at Bacup.
A Lancashire Fire and Rescue Service spokesman said: “We are hoping it rains, as the land is so dry.”
A helicopter had to be commissioned by United Utilities, which helped to save some woodland areas.
Rangers used specialist 4x4 vehicles and local knowledge of the terrain to transport fire brigade personnel around the affected areas.
Firefighters have continued to dampen down moorland in Belmont and Anglezarke for fear they could go up in flames again.
Spokesman John Taylor said: “Even though the majority of the fire has now been put out, it’s still a very labour-intensive job to keep it under control.
“The crews are operating over several acres of land and, if a small fire is left to burn out, a gust of wind could cause it to spread into a raging fire again.”
Crews expect to be at the scene for a few more days yet, as they use water from Anglezarke reservoir to extinguish small pockets of smoke and flames which are appearing in the grass.
Mr Taylor added: “To find flames which are below the surface of the grass, they have thermal imaging cameras, and are penetrating the water below the surface.”
The weather forecast predicts rain over the weekend, which Mr Taylor said will be a welcome aid to the firefighters’ efforts. The area near the reservoir has been cordoned off, but members of the public are hiking and taking part in leisure activities in other areas of Anglezarke.
Bryan Homan, United Utilities’ Catchment Operations Manager, said: “In all likelihood the cause of the fires will have been something which has been carelessly discarded – possibly a cigarette or a disposable barbecue set – which in this kind of weather have the potential to create fires and cause a lot of damage in a short space of time.
“Consequently we are urging visitors to our land to please act responsibly when visiting countryside areas - particularly in regards to the risks posed by cigarettes.”
It is expected that the affected areas of moorland will recover quite quickly over the next few weeks, but arrangements will need to be made to replant trees where woodlands have been damaged.