Josh Heslop, from Ingleby Barwick, wanted to raise money for the Great North Air Ambulance in memory of Adam Mclauchlan of Stockton, who was a huge supporter of the service.
The former truck driver, passed away from lung cancer in January 2011 and grandson Josh decided to do two things to raise money.
One was to cut off the ponytail he had been growing for four years and the other was to climb the landmark peak.
He said: “My granddad used to tease me about my ponytail and he joked that he’d chop it off, which made me grow it more.”
Imeson’s Barbers in Thornaby cut it off for free, as well as sponsoring Josh. He then climbed Roseberry Topping with his 11-year-old girlfriend Charlotte Laidler.
“When I saw the hill I thought it looked massive and when I got back down I looked up and thought I can’t believe I’ve climbed that,” he said.
Josh also got a local pub, the Golden Eagle in Thornaby to hold a name the teddy bear competition which raised a further £40 for his cause.
Mum Zoe Heslop said: “Josh has done this all himself - from deciding to raise money, to his fundraising ideas and gaining sponsorship. I am so proud of him.
"He was very close to Adam and at the top of Roseberry Topping he said ‘I’ve done this for you granddad’.
"He now spends a lot of time with his grandma, Glynis, chatting about him.”
Mandy Drake, head of fundraising at GNAAS, said: “Josh has made a lovely tribute to his granddad.
“The money he has raised will go towards keeping our aircraft in the sky and Josh should feel proud that he has helped towards saving lives in the region.”