Authorities said it took emergency crews two hours to rescue Wyatt Kauffman after he slipped on the Bright Angel Point trail on Tuesday.

The boy was airlifted to a Las Vegas hospital for treatment of nine broken vertebrae, a ruptured spleen, a collapsed lung, concussion, a broken hand and a dislocated finger.

"I was up on the ledge and was moving out of the way so other people could take a picture," Wyatt told Phoenix TV station KPNX.

"I squatted down and was holding on to a rock. I only had one hand on it.

"It wasn't that good of a grip. It was kind of pushing me back. I lost my grip and started to fall back," he added.

Rescue crews abseiled down the cliff to fetch the injured boy out of the canyon in a basket.

"I just remember somewhat waking up and being in the back of an ambulance and a helicopter and getting on a plane and getting here," Wyatt said from hospital.

The boy's father Brian was back at their home in North Dakota when he heard about his son's fall and rescue.

"We're extremely grateful for the work of everyone. Two hours is an eternity in a situation like that," Mr Kauffman said.

He said Wyatt and his mother were on a trip to visit the national parks when the fall occurred.

Mr Kauffman said his son was discharged from the hospital on Saturday and was being driven home.

"We're just lucky we're bringing our kid home in a car in the front seat instead of in a box," Mr Kauffman told KPNX.