The walker was trapped under a rock on the Gribin ridge. Photo: Ogwen Valley MRO

A walker was injured when he was trapped under a rock dislodged by one of his companions on a Snowdonia mountainside.

One of the party managed to lift the boulder enough to allow the unconscious man to be freed.

The incident happened on Sunday after a couple from Merseyside and their regular hillwalking partner had enjoyed a day climbing Tryfan, then the Bristly Ridge to Glyder Fach.

The three walkers were descending the Gribin ridge between Glyder Fach and Glyder Fawr in deteriorating weather when the accident happened.

Ogwen Valley Mountain Rescue Organisation was alerted by North Wales Police about 5.30pm.

Chris Lloyd of the rescue team said: “On the rocky start to the descent the man dislodged a large slab of rock on which his female partner was standing.

“She was knocked off balance and fell a few feet below suffering a minor knee injury.

“Meanwhile the man fell and he was then trapped underneath the rock. He was knocked unconscious having received a head injury. Their friend was able to lift the rock sufficiently to release the casualty.

“The casualty regained consciousness as first aid was given. Without mobile phone signal, the friend had to make his way all the way down to Idwal car park where fortunately he was able to get assistance from the national park warden.”

The Ogwen Valley team requested help from the Caernarfon Coastguard helicopter. Mr Lloyd said: “Despite low cloud and strong winds, the helicopter was able to lift a hasty team of three up to the ‘football pitch’ high up the Gribin. A turbulent landing was made and the three headed off up the ridge to the casualty site.

“The helicopter returned to Oggi Base to pick up another four team members and rescue equipment for another impressive flight and landing. The woman was flown down to Oggi Base for treatment and care, where she met her friend.”

On the mountain, the walker was treated by team members for his head and suspected back injury and placed in a stretcher. Mr Lloyd said: “In deteriorating weather, the Maritime and Coastguard Agency helicopter eventually managed to lower the winchman to the stretcher party for a quick evacuation. The skills of the helicopter crew saved a long and difficult stretcher carry from about 900m up the mountainside.

“The casualty was flown down to hospital in Bangor and the seven team members on the hill made a wind-blown descent to the valley.”

He said because of a high probability there would be a long stretcher carry, members of Aberglaslyn Mountain Rescue Team made their way to the Ogwen Valley team’s base on standby.

Mr Lloyd added: “A warning to all of us is that even the largest pieces of rock can be loose and fall. This was extremely unfortunate as the party were well equipped and experienced.”

The rescue ended about 9pm.