Two hours or so from Milngavie into the West Highland Way, we encounter something that may or may not pose a risk to life and limb.

Standing on a rise, within sight of the 492ft-high hill Dumgoyach, near Blanefield, a cow is watching us intently.

"I think that's a bull," says my friend, warily. I look again. "No," I argue uncertainly, a townie to the core. "It's a cow. Isn't it?"

"It doesn't have an udder. Seriously, that's a bull. If it charges us, we're in trouble. We should chuck a stone at it if it charges us," he adds, half-jokingly.

I glance at him dubiously and leaf through my guidebook. "You're not serious," I tell him. "It says here we should treat wildlife with respect."

In the event, we walk past the cow/bull/whatever, careful not to make eye contact, ready to scarper if it charges us. It's a beautiful day - the sun is beating down and the only sound is two pairs of boots scrunching across the terrain and water sloshing around in a bottle purchased the previous day from a shop in Glasgow's Sauchiehall Street. I think I see a buzzard, but I might be mistaken. Townie to the core.

It was 40 years ago next year that plans for Scotland's first long-distance path got the go-ahead. On September 9, 1974, President Gerald Ford was being booed in public for having given a pardon to the disgraced Richard Nixon. On the other side of the Atlantic, the then Scottish Secretary of State, Willie Ross, was approving plans for a 95-mile walk between Milngavie and Fort William.

A key role was played by an geographer named Fiona Rose, who spent a year doing a ground survey of the route in the early 1970s. She walked nearly 1000 miles, surviving - according to a report in The Glasgow Herald - frostbite, midges, exhaustion and irritable landowners, and wearing out several pairs of boots. But her work was vital, and laid the foundation of the proposals drawn up by the Countryside Commission for Scotland.

"It is expected," the commission said, "that [the Way] will offer the public between four and five days' walking, and provide them with a real sense of achievement." The route would take them through a "variety of countryside which becomes more rugged as the route goes north".

Fifty of the miles were along rights of way, 19 along existing paths and tracks, and six miles alongside roads. Seventeen miles of path needed to be created. The cost was put at £36,000 but by 1979 this figure had increased considerably.

It was an intriguing idea but not everyone was taken with it. Some walkers and mountaineers objected that their solitude would be eroded by casual walkers, that the Highlands would be "domesticated", that the Way would amount to a "walkers' motorway". The commission dealt with such claims; and planners and leisure experts who had been involved with the project were generally enthusiastic, while suggesting its future use and development would have to be monitored.

On October 6, 1980, the Way was opened. Fiona Rose was by this time living in New Zealand. "We only wish she could be here," said the commission's spokesman. "She did a tremendous job."

Today, the Way is remarkably popular. A fortnight ago Lonely Planet's 1000 Ultimate Adventures described it as one of the world's finest treks, with "killer views". Every year, more than 80,000 people walk it, half of them doing the entire route, and local economies benefit to the tune of £5 million.

Guidebooks such as the one I used - West Highland Way by Charlie Loram - hymn the praises of the Way for, in his words, containing some of the most fabulous scenery in Britain. The route is knee-deep in history, too.

Jimmie Macgregor, 83, has been a hillwalker since his school days in Springburn. One of Scotland's best-known broadcasters and folk musicians, he was familiar with three-quarters of the route between Milngavie and Fort William before it was christened the West Highland Way. In the Way's first full season, in the spring of 1981, Macgregor walked it for BBC Radio Scotland, and in his rucksack was a tape recorder.

"They wanted one half-hour programme but I came back with enough material for 10, and they edited it down to six or seven," Macgregor says. "It got a terrific reaction and I wrote a book [On The West Highland Way], which ended up topping the Scottish booksellers' list.

"We made a TV series about the Way, which got a fantastic reaction - I think it got 25% of Scotland's viewers."

It's still a point of pride with Macgregor that he did not confine himself to dry facts and figures; instead, he discussed things he already knew quite a bit about.

"I talked about the wildlife, about Rob Roy, Bonnie Prince Charlie, and about old traditions, like the Highland funerals they used to have at Inchcailloch [island, offshore from Balmaha on Loch Lomond].

"Roy Roy had an estate up at Inversnaid, and when somebody important died, the body would be put on to a war galley and they would sail ceremoniously down the loch and bury them at Inchcailloch, the MacGregors' burial ground.

"I spent a night at Inversnaid with the Loch Lomond Angling Assocation and got some great stories from them. I also talked about the Glencoe massacre, and walking across Rannoch Moor, which was quite spooky. I did it in pouring rain, and it's a pretty long slog from Inveroran to the Kings House. You just have to get your head down.

"I don't have a favourite part as such; the dramatic bits are Glen Coe and Rannoch Moor, and maybe the Devil's Staircase, which goes up from Glencoe and takes you on a big descent to Kinlochleven."

It's been at least a decade since Macgregor last did the Way, but it still has a place in his affections. "The great thing for me," he says, "is that it led on to other great Scottish walks, and then walks in Ireland, Canada, Yosemite, the Arctic - the list goes on."

A mile or so on from our encounter with the cow/bull/whatever, we meet a man in his 70s named Kenneth ("just Kenneth"). He has been doing sections of the Way for eight years, and is making his way from Drymen to Milngavie. "Lovely day for it," he says. He is formidably fit, as is evidenced by the speed with which he becomes a speck on the horizon.

It is a gorgeous day. Close to Dumgoyach, we turn and go back the way we came. Today, like Kenneth and so many others, we are just walking a stretch of the Way.

Over an al fresco lunch I look at my guidebook. "Stunning views," it says of this particular stretch. "The Campsie Fells to the east, the volcanic conical hills of wooded Dumgoyach and Dumgoyne beyond, all the way to Ben Lomond on the horizon, the start of the Highlands."

We retrace our steps, down past Craigallian Loch, back through Mugdock Wood. Two miles from Milngavie we spot the year-old Craigallian Fire Memorial. On this spot, legend has it that the Craigallian fire remained alight for a decade from the late 1920s and that there was always a welcome and a mug of tea to be had for the out-of-work wanderers who escaped from the Great Depression.

The fire gets a mention in Weir's World, Tom Weir's 1994 "autobiography of sorts" in which he quotes Matt Forrester, a friend and climber: "It had all the grandeur of the Highlands, yet it was only 10 miles from Glasgow. At all seasons it was a howff for walkers and climbers … Coming along the track of a winter's evening, the glow of light and the merry shouts of laughter brought joy to the heart." Weir described it as a "university of knowledge on the great outdoors".

According to Charlie Loram, some of the so-called fire-sitters went on to fight in the Spanish Civil War. Others campaigned for greater access to the countryside.

Nearby we encounter a group of three German students in their early 20s, laden with backpacks. An Englishman named John Heald, in his mid-20s, has come to walk part of the Way during his summer holidays. "Breathtaking scenery," he says. "My only complaint is these midges."

In Mugdock Wood, the late-afternoon sun, filtered through the trees, turns the Allander Water bed into the colour of spun gold. It is an arresting sight.

Years ago, my friend and I walked a more rugged stretch of the Way, one that took us across the Devil's Staircase - an 850ft (259m) climb that is, says Loram, feared by walkers. "Although it's a sustained climb," he writes, "it's not nearly as hard as the name would suggest." Back then - younger, fitter - we still found it hard going.

Herald readers have been keen to share their memories. Robert Arnott made the walk in 1992, in the three months between school and university. He was 18. He and his friend Alastair got as far as one mile east of Drymen, where they camped. It was here that Alastair chose to come down with gastroenteritis. "What time of night it was exactly I don't know, but Alastair was violently sick in the tent," recalls Arnott. "Then he went outside with practically no clothes on, and he was violently sick in the field. Further details I'll spare, but it was dark, and he trod in a cowpat in his bare feet on the way back to the tent. I was in hysterics."

The duo hit the trail again in 1993. A sleeping mat was stolen at Balmaha. Rowardennan youth hostel "was full of ugly people and wearers of German army jackets". An overnight camping spot opposite Island I Vow was invaded by slugs. Alastair's feet became increasingly sore, and he was fed up. They parted company at the Drovers Inn, at Inverarnan, by Ardlui.

Arnott continued on his own. He met a man named Holger from near Stuttgart; had the "worst haggis supper ever" at Kinlochleven; rolled on to his glasses inside his tent; got soaked to the skin; and, finally, completed the trail and found himself on the Fort William-Glasgow train. En route, he stopped in to call on Alastair. The door opened, at which point the strip of Elastoplast holding Arnott's glasses together gave way, "leaving one lens dangling on the end of its plastic wire, swinging from the side in front of my face".

Gavin Cockburn, from Troon, sent us two photos from his walk in July 2006 - "a great reminder of not only a fabulous summer but also a great time in my life spent bagging Munros and seeing the best parts of our beautiful country".

In the first photo, Buachaille Etive Mor is the star; Cockburn's wife Carrie, best friend Kenny Malone and his wife Lauris are the also-rans (his words, not mine). He recalls a night spent in the walkers bar at the Kings House in Glen Coe watching Germany beat Argentina in the World Cup. The other photo shows him descending Conic Hill after 20 miles of walking on the first day. "A pint in the Oak Tree Inn, Balmaha, was the most well deserved I've ever had."

Mark Wynn, now in Inverness, came up from Manchester to walk the Way just as it was officially being opened. He was raising funds for the Institute for the Blind, and was accompanied by his younger brother.

"As we walked alongside Loch Lomond we were joined by an elderly man who we later learned was Tom Weir," he writes. "He was intrigued about this new long-distance footpath and was exploring a little of it. He subsequently wrote an article that appeared in The Herald with a photograph of us two bedraggled walkers … A couple of days later, we walked some distance with a young couple who were dancers with the Scottish Ballet. This was their way of keeping fit."

Amanda McAra was doing the Way last July with her 10-year-old son, Andrew, when he sprained his ankle on Conic Hill. The next day he was given painkillers and a set of walking poles but couldn't go on. After a couple of nights' rest he was able to continue, to the point where he "practically ran up Devil's Staircase" en route to the finish in Fort William. He managed to raise more than £1000 for Springfield Cambridge Church in Bishopbriggs. This July he and his mother cycled the Way, and did the 96 miles with only one puncture.

This summer, Graham Lironi, his son Michael, who was celebrating his 21st, their friends and two labradoodles did the walk in reverse, from Fort William, with a surprise family party planned for Michael at Bridge of Orchy Hotel. But July 19 was, says Lironi, "the hottest day of the year in the hottest year for a good seven years".

They found themselves on Rannoch Moor, exposed and exhausted, with nothing in the way of shade. It was torture. The party was due to start at 6.30pm. At 7.30pm, Lironi, his two friends and the dogs were two miles away, lying in a frazzled heap, waiting for Michael and his friends to catch up.

Lironi tried to get a signal on his phone to tell his wife what had happened. Eventually, he reached his daughter and the hotel manager came to their rescue in a 4x4.

"I don't remember much about the meal. I don't remember anything much about the rest of that evening. Or the following day," he says. "The Way was glorious and all the people we met were from overseas: Germans, French, Spanish, Scandinavians, Americans - hell, even English."

Helen and Mike Paddon, of Aberdeen, lost their jack russell-border terrier cross, Davey, on a rain-drenched walk in May 2011. Halfway between Kinlochleven and Fort William, on their final day, Davey hared off after spotting a sheep. It was the only time he'd been off the leash.

The couple searched for him, but in vain. Davey was gone. They were absolutely frantic. The next day they put up Missing posters in Fort William and all the places they'd visited. A picture of Davey was put on Facebook. The local radio station broadcast hourly alerts.

Five days later, the couple were back home. A farmer rang to say he'd seen Davey on his farm, but by the time they arrived, he had scarpered. This set the pattern for the next three weeks. Then a B&B owner at Onich said he'd managed to trap the dog in his garage. Result: an emotional reunion.

"The support from the community and all the people associated with the Way was amazing," says Helen. "We were shown so much kindness. After Davey was found we even received a Welcome Home card from the primary school in Kinlochleven …everyone was so taken with the story." Postscript: the man who found Davey declined the reward money, so the couple gave it to Glencoe Mountain Rescue Team.

A few days after Milngavie, my sister Jennifer and I spend a tranquil Sunday walking the seven miles from picturesque Balmaha to Rowardennan, fortified by a quick breakfast at the Oak Tree Inn. It's an even more scenic walk than my first part: Loch Lomond, clear and sparkling, is never far away, and there are interesting walks through re-established woodland. We meet a family out walking their jack russells - one is called Jack, the other Victor. We have coffee and scones at the Rowardennan Hotel. It's neither as warm nor as sunny as it was on my first day, but the scenery makes up for it - even if the last half-hour to the hotel, through woodland, seems to take for ever.

"I loved it," says Jennifer. "It inspired me to think about doing the whole route. But I'd recommend that people do a taster part of the walk before tackling the whole thing."

At one point we meet four women who are doing the 96 miles to raise funds for Macmillan Cancer Support. A remarkable number of people walk the Way to raise money for good causes.

Some more contributions from Herald readers: Anne Macleod and her husband Ted walk the Way once, sometimes twice a year. Ted has completed it 24 times, Anne 22. "I'll never forget my first time," she says. "It rained constantly. When we reached Rannoch Moor I'd never been so miserable in all my life and had never tripped up so much. My feet were covered in blisters.

"We stopped to camp for the night and went into the climbers' bar in the Kings House for a heat and a drink. Ted went out to set up the tent but, unknown to me, booked us into the hotel. What a relief.

"Next day, my boots were still soaked and weighed a ton, but we set off again over the Devil's Staircase down to Kinlochleven. The path on the other side of the Staircase was like walking through a rocky burn. By this time the soles of my boots had started to come off and Ted tied them back on with cable ties … Needless to say, when we walked into Fort William the sun was glorious. After that week I was hooked."

Speaking of the Devil's Staircase, Archie Bell, from Stranraer, recalls: "While walking up Loch Lomondside I met a party of medical men and their wives. We met again the following days. Halfway up the Devil's Staircase - in my opinion, the most difficult part of the route - I was sitting on a boulder having a rest when they passed me again. One of the ladies said: 'Archie, do you bring your boulder with you? Every time we meet, you're sitting on one having a rest.'"

Back in 1968, Kinlochleven was described by the moutaineer and writer WH Murray as the "ugliest [place] on 2000 miles of Scottish coast". Today it is a major outdoor activity centre, with such facilities as The Ice Factor. Reader Robin M Brown is among the many walkers who believe the village has raised its game in recent years and almost qualifies as a hidden gem. Derelict buildings have been removed, and landscaping and several welcome facilities have been introduced.

Andy Lowndes walked the Way recently in memory of his wife, Jennifer, who died last December. Together with friends including Jennifer's nephew, Scott Young, he raised £4600 for Cancer Research UK.

Lowndes's entertaining, illustrated blog (he says he'd have done the Way in half the time if he hadn't stopped to take so many photographs) is at whw4jct.blogspot.co.uk and is worth a read. It ends on a poignant note: "A sense of achievement was tinged with a bit of sadness. My darling Jen would have been proud of all who took part with us. She would also have thought we were a couple of pelters for even attempting it."

John Dickson sends an interesting story of the walk he did in 1992 with his brother, Alan, and two friends. It was, he says, "the first time in my adult life that I had taken a break without my lovely wife, Mary, who, we discovered just weeks before we set off, was pregnant at the age of 40 with our now 21-year-old daughter, Kathleen".

Dickson writes of the sense of liberation the four felt when they paid a small sum each to have their heavy bags forwarded to the next stop by a farm worker in an old Land Rover. The liberation was such that they even conquered the Devil's Staircase with relative ease. It was, he says now, "one of the best weeks of my life".

Chuck O'Connell gets in touch. "In 2005 a group of us, former US Marines now residing in the UK, and members of Marine Corps League Detachment 1088, which is based in London, undertook the West Highland Way, the section between Bridge of Orchy and Fort William," he writes. "Good friends undertaking a challenge. Beautiful scenery, excellent weather. Only shame was that we didn't have time to complete the entire route."

Sometimes on the Way you meet characters. Just ask John Delaney, from Lochwinnoch, Renfrewshire. Delaney did the walk in 2008 with an Irish friend in order to raise money for the Teenage Cancer Trust, which he has supported since the death of his son, Andrew, in 2003 aged 15.

Along the way they encountered one particular character, "Donald". At various points they saw him dressed in white woolly joggers and sports jacket, his rucksack an old canvas bag with drawstring; they saw him washing his socks in a burn; learned that he was sleeping rough under hedges and bridges. At the Kings House they heard Donald declare: "Ah'm a free spirit!" before adding: "That's how Ah lost ma girlfriend."

Dougie Irving used to think the Way was a "touristy thing to do" but then in October 2005 he walked it for the first time. He has since become a bothy enthusiast and a member of the Mountain Bothies Association. "The thing about the Way which made it so special for me." he says, "was that I was passing through all these iconic places along the A82 which I had been through so often before on the road." The place-names themselves, from Tyndrum to Bridge of Orchy and Rannoch Moor, have a great resonance for Scots, he says.

"I was particularly anticipating the section of walk from Bridge of Orchy west and north, over part of General Wade's old military road, and skirting the foothills of the Black Mount. It didn't disappoint … Most memorable of all was the sound that night of stags in rut. The constant bellowing of deer close by made for a primeval experience, and at times the stags sounded so close that I feared for my life. That experience will stay with me for ever."

Irving continued his walk beyond Fort William, along Loch Arkaig and up into Knoydart before reaching Glenelg, where he visited an old friend. "Since then I have attempted several more long-distance hikes in other parts of Scotland, but nothing has quite compared to the first time I walked the West Highland Way, and the sense of achievement."

Alastair Black, who did the Way two years ago with his son Cameron, then 12, reflects: "The sense of camaraderie is kind of special - it's as if you enter a more trusting, egalitarian world, where the shared effort has a bonding effect. I'm thinking of the Honesty Stations early on where refreshments are left out and passing walkers are invited to help themselves for a recommended price. I'm thinking, too, of the sandwiches and crisps we found left behind in Doune bothy with an accompanying note that said: 'Good food,' and a passing walker donating a precious blister plaster to a dejected young lad sitting by the side of the path with a badly bleeding heel.

"A few final impressions of a truly enjoyable experience: the burn at Inversnaid in full flood is spectacular; the magical sense of remoteness; the sense of walking into Scotland's past - the Craigallian Fire, the drove roads and Thomas Telford roads and bridges, Robert the Bruce battle site, Glen Coe and so on; the remote beauty of Loch Tulla."

Gordon Abbott sent a photograph of himself and his son Matthew, then 14, from their walk in 2010. "This was a fair challenge for him and he (we!) found it fairly hard going, particularly the day of the photograph as it was absolutely torrential.

"The photo is at the bottom of the Devil's Staircase and shows the conditions pretty well - but it only tells part of the story, as it was taken by a woman who was out running in shorts and T-shirt. She then set off up the Devil's Staircase at a fair pace and was never seen by us again. We watched in disbelief, with the weather not putting her off. We were soaked to the skin and pretty cold by the time we reached Kinlochleven, so we could only imagine how she had fared."

Ah, running the Way. Once or twice to Dumgoyach we were overtaken by runners. They looked terrifically fit and dedicated. Gareth Bryan-Jones has walked the Way twice with his wife and friends and has twice taken part in the West Highland Way Race.

"In 2013, 180 or so people set out from Milngavie and nearly 149 completed the route in between 15hr 7min and 35hr. When I went through Glen Coe the weather was fantastic - sunshine, clouds, rainbows and tremendous lighting effects."

Bryan-Jones recommends the history of the race as a fascinating story - it's at westhighlandwayrace.org/history.htm. More than 800 people have completed the race, and many have submitted blogs.

According to the website, the event started when athlete Duncan Watson challenged Bobby Shields ("a man with many trophies to his name, including the famed Ben Nevis race") to a head-to-head race along the Way on June 22, 1985. It was a titanic struggle, and Watson and Shields decided it was better to pool their resources. They crossed the finishing line together after 17hr 48min.

The following year saw the race being opened up to other runners. It has continued to flourish. This year, it was won by the Scottish ultra-distance international Paul Giblin, from Paisley, in a new record time of 15hr 7min. This bettered the existing record set by Terry Conway the previous year by more than 32 minutes.

I look at that time again. Just over 15 hours to run the entire route? Good luck to you if you're fit enough to carry that off. Other people, however, prefer to take their time on the Way, where they can enjoy the scenery and the camaraderie, chat to people from foreign lands, or even simply contemplate the safest way of walking past a cow that might just be a bull. n

Visit west-highland-way.co.uk