Fire crews in south Wales have dealt with 623 deliberately-set grass fires since 1 April.
Now residents have approached South Wales Fire and Rescue Service to volunteer as "spotters".
It comes as 45 firefighters are tackling one fire, covering 148 acres (60 hectares), in the Swansea Valley.
Crews were called to the mountain fire at Godre'r Graig, between Pontardawe and Ystalyfera, at about 08:00 BST.
On Monday it was revealed that children as young as 11 are among those who have been arrested for starting blazes in south Wales.
Gareth Davies, a fire service group manager with responsibility for Rhondda Cynon Taff and Merthyr, told BBC Wales' Good Morning Wales programme residents had "had enough".
"Residents are contacting us... to see if they can get involved, if they can help us and support us in terms of maybe going out onto the mountains.
"A number of them are getting together and spotting for us... where the fires are being located and trying to locate where the perpetrators are and pass that on to the police.
"So that is a positive and I would implore people if they do want to get involved with us then by all means go to their local fire stations and we can work together to hopefully stop this happening."
A community group calling itself Mountain Fire Prevention Team (RCT) has been set up on Facebook.
The group said its key aim was to "help the fire service and the police by trying to prevent mountain fires" by organising foot patrols along the mountains.
The group's Facebook profile reads: "The fire service does not have the man power to patrol the mountains, so if we were able to do it, it would take some strain away from them."
The RSPCA has also warned the fires were posing a "great risk" to wild animals, especially at a time of year when many are very young and unable to escape fires.
On 14 April the charity was approached by South Wales Fire and Rescue Service after a burnt hedgehog was found in Pontypridd.
A spokeswoman said, "Fire not only kills wildlife but will also displace surviving animals from their territory, creating problems such as territorial disputes when they move on to new areas.
"Species that live in dens, burrows and warrens can become trapped by the flames and smoke and suffocate."
Residents from communities across south Wales have rallied together to try and catch arsonists who deliberately start grass fires.