Channels have been found gouged into the ground and washing machine-sized boulders dislodged near the top of 909m (2,982ft) Leum Uilleim.
Allan Macleod, head stalker at Corrour Estate, said at first glance it looked like the damage was caused by a large mechanical digger.
But he said this was impossible given the location.
The nearest place people can reach the mountain is more than a mile away at Corrour Station, one of the UK's most remote and highest railway stations. There is track, but not a public road to the station.

Mr Macleod said he believed the only plausible explanation for the damage was a lightning strike.
He said there appeared to be a point of impact near the mountain's summit. The channels began less than a metre away and may have followed small water courses on the hillside.
Mr Macleod said: "The boulders were two or three feet square in size and the channels in the ground were up to 40ft long.
"Also, any diggers working on Corrour I would have known about, especially in such a remote location."




Reader Comments
Life is SO interesting!!
R.C.
It was strange but I could see the flash (outside) and thunder (instantaneous and everywhere) and I was across the room and the computer box 'hopped off of the table' (odds ~ 95%, as I don't claim to be absolutely certain about ANYTHING.)
But, the above 'boulder tossings' seem to involve this same unrecognized ability for electricity to somehow magically turn into kinetic energy, and I've remained baffled since that day, especially this the computer wasn't damaged - I think its power might have shut off from the fall.)
RC
I DO really appreciate you spending time on this; back when it happened, I went through the same thing but no answer was ever found - I even emailed some 'lightning engineer expert' and never heard back.
I'm going to rest and call it a continuing proverbial conundrum.
Thanks again!
RC