Esther Brauer began work at Kylesku post office in Sutherland in the year of the Queen's coronation, and has now decided to call it a day at the age of 83.
For more than three decades, she has worked from one of the UK's smallest branches - an 8ft by 6ft hut in her garden.
Mrs Brauer said she has made many friends over the years thanks to her role at the heart of the community.
"I have loved the job so continued as long as I could, but at 83 it is time to retire," she said.
"I was delighted to pass 60 years' service last year.
"The service has been a lifeline to the community, because we are so remote. People need to collect their pensions and be able to send their mail.
"Also I have made a lot of friends through working here. I still get Christmas cards and postcards from around the world from people who have visited."
When she began work in 1953, Mrs Brauer first operated her six-days-a-week service from a post office that was part of her house.
But when she moved house 31 years ago and started working from a shed in her garden, the fixture became quite a local attraction.
"It's quite something for people to see, a post office in a shed," she said. "During the tourist season, a lot of people visit and want to see round the place."
Originally from Elphin, a few miles further south in the Highlands, Mrs Brauer settled in Kylesku aged 18 when she married her first husband Ian Clark, whose parents ran the old post office from their home. When they moved further north to Tain, she took over the job.
After her first husband died, she married Walter Brauer, former head ferryman at Kylesku, and they moved a mile along the road to his home at Ferry House, where she has run the post office from a shed since 1983.
Until she was 60, she was also the local postwoman, delivering mail on an 18-mile route.
Since news of her forthcoming retirement emerged, the subpostmistress has been inundated with thousands of cards from well-wishers from across the UK.
She received a long service award from the Post Office last year and will receive a special commendation from the Scottish Parliament this year.
Post Office area manager Kenny Lamont said: "I have known Esther for the past 15 years, a fraction of her career with us. Esther is well known and very highly respected in this small Highland community and everyone is very sad to see her go.
"Esther has shown incredible dedication to serving her local community. We have a small number of exceptionally long-serving subpostmasters and mistresses and Mrs Brauer ranks amongst the very best of them, and she is a credit to our business."
With Mrs Brauer's retirement, the shed will close, but a local postmaster will operate a twice-weekly service nearby.