Liz Smith, who represents Mid Scotland and Fife, ascended Slioch, on Loch Maree. It was the 283rd peak she required to become an official Munroist.
The former teacher has raised more than £7000 for mountain rescue teams, the Mountain Bothy Association, the John Muir Trust and the RNLI
Ms Smith said: "I am delighted, and probably also a bit relieved, to be at this stage in what has been a long journey for me."
She added: "I was always attracted by the magnificent grandeur of Slioch in what is one of my favourite areas of Scotland, and so that is why I kept it till last."