THE October 7 event, organised by Reach for the Rainbow, aims to raise $100,000 as part of its goal to fund a world-first Early Intervention Hub, where parents of children with a disability and delay can get help from specialists.
"We are absolutely overwhelmed with the phenomenal volunteer support we have received," co-ordinator of the event and current people's choice NSW Woman of the Year, Yvonne Keane said.
"They are the backbone of Run for the Hills," she said.
"Without their support we simply could not stage this event."
One major contributor has been the Rotary Club of Castle Hill, which has worked with the charity for eight months.
Rotarian Mike Blair said the club is "delighted" to throw [its] support, and volunteers, behind the event.
"It is a truly worthy cause and we are proud to be foundation partners for this event," he said.
A small army of eager assistants from the Hills Adventist School will also help on the day, doing everything from collecting donations to handing water bottles to passing runners.
"I'm really looking forward to helping out," year 10 student Jessica Shipton said.
"The only thing you get back is happiness."
Classmate Lyiona Innis wants to be "a good example to [her] school". "I'm not scripted here," she said.
On the Castle Hill main street, where the run starts and finishes, there will be a free festival for families all day hosted by Castle Towers, and features carnival rides, an animal farm and a giant AMF bowling set, as well as a free concert, headlined by Prinnie and Mahalia (pictured) from The Voice. To find out about the course and registration, visit runforthehills.com.au.