Running Mount Marathon with limited vision

Running up and down Mount Marathon has become a yearly event for 12-year-old Rennick Heatwole. He first ran the Junior race in 2014.
“It was hard because I was working to do my best and not fall off the trail,” he said.
Rennick Heatwole finishing Mount Marathon in 2016
Rennick is significantly visually impaired.
“When I stick my arm out everything behind it is a blur, on the trail that’s kinda tricky,” he said.
Rennick was born with an eye condition called optic ner