IN primary five, we learned Kenneth McKellar’s “Song of the Clyde”. “Of all Scottish rivers it’s dearest to me,” I sang with 60 other Glaswegian school kids, “it flows from Leadhills all the way to the sea.”

That is not quite right. The streams that flow from Leadhills through corries and cleuchs to Elvenfoot and Abington are not the Clyde – they only feed it. Some say the river’s source is Watermeetings, where these streams meet others by a quiet road to an old convent. Others say it is a stream called Little Clyde, which thousands of people cross every day on the M74.

I parked at the entrance to Clyde Wind, one of Europe’s largest wind farms, and crossed a knobbled grazing field to find the burn whose babble is drowned out by the rush of road. Its peace has always been disturbed. This field was once a Roman marching camp, and it is easy to imagine it as a kind of ancient service station for soldiers heading north. Now, it is the site of a DVSA lorry weigh station.

I followed the burn upstream through a wood, under pines whose arthritic stumps and broken wands were draped with moss and lichen, out onto the hillside where it first surfaces among towering turbines. These Clydeside industries – logistics, energy, lumber – were as important in ages past as now.

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From here, the Roman Road follows the Clyde to Crawford, where a ruined castle provides views of the interknotted river, road, and railway. Further downstream, Tinto climbs above, a lonely hill that was a strategic point for watching over Clydesdale since at least the Bronze Age. From Tinto, and from the child-size Quothquan Law beside it, you can see the river feed the fertile meadows of Lanarkshire and flow down from the hills to the south.

From this perspective, it is clear why good roads were always vital to connect this watershed dale with Lanark and Biggar, and the cities beyond them. In 1766, the erstwhile Jacobite James Steuart wrote about roads along the Clyde. Improving them, he said, would allow the treasures of the hills and the grain and textiles of the mills to reach their markets. It would support small manufacture and better-paid work for the people. In the north of England, he said, pioneering roads and other public works in Rochdale and Burnley allowed industry to prosper among “barren hill country” that was “no better than that which in Scotland lies from Crawfordjohn to Leadhills and Moffat”.

When low wages pressured them to go elsewhere, good connections let people keep the countryside as home. Roads must suit heavy wagons, Steuart said, not just horses. They must be properly covered, or carriages would cut through and cause potholes. Local authorities in charge of roads “generally let them be too far gone” before repairing them, but Steuart had a plan. Not only should roadworks provide regular local jobs – but if on every stretch of road someone was employed to do repairs, then roads would be robust, workers fairly paid, and locals not cut off.

Between Biggar and Lanark, the Clyde flows north-west then swings back southwards, creating a shape roughly like a bowler hat, with bridges at its eastern and western brims and another at the top. One drizzly Saturday, I drove to this Clyden cranny, and on the road between the bridges at Hyndford and at Thankerton, a sign invited me to “Discover Carmichael”.

Since it was both lunchtime and raining, I stopped, and found a tourist shop and café (friendly, if a little frumpy) among the buildings of a working farm. Marie, the shop-assistant-cum-tour-guide, told me of Covenanting conventicles and Jacobite adventurers. Every few years, she explained, Carmichaels of the world gather here to renew their clan connections and replace their tartan ties. The rest of the time, the inheritor of the ancient chiefdom runs a small family business specialising in sumptuous venison.

The National: LANARK, SCOTLAND - MAY 24: a general view of the falls of Clyde Wildlife Reserve on May 24, 2016 in Lanark, Scotland.  Shot for a Herald Magazine Feature (Photo by Jamie Simpson/Herald & Times) - JS.

AS I poked about the antiquarian books I overheard a customer, on his way to a dog show in Lanark, saying the rain was not heavy, but thick mizzle. I soaked it up, driving past drooping snowdrops to explore the mills near the western bridge, before I headed to higher and, it turned out, dryer ground at Pettinain.

I’d in a 19th century journal that this village provided excellent views across the Clyde to Carstairs, but what struck me first were the peculiarly red roads. My inspection of the infrastructure was obviously unsubtle, as a local couple gardening on the village green asked if I was a surveyor. When I said no, but I was intending to write a newspaper article, they leant on their spades and told me about the roads, made, Susan explained, from red granite from the local quarry at Cloburn.

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When the tarmac erodes a bit, the road glows at night, and the children scuff their knees on the hard granite. But not for much longer – they’ve stopped making them that way. Lament led to grievance, and soon Finn, spade in hand, was telling me the “saga of the bridges”. The Carstairs bridge was shut despite long local protest. Without it, the only way west was over the steep one at Thankerton (“you need crampons and an ice axe to get over it”). Locals had been trying to put the village on the map, but if one more overweight lorry crunched into the bridge, he said, this community would be that bit more cut off.

Growing up in Linlithgow, the fastest way for Finn to reach his family in Yorkshire was through Thankerton and other places like Quothquan. Now, folk from the Central Belt have never heard of these places. After some further peregrinations, I was warned not to get the locals started on the roads.

But the roads of East Clydesdale are, I thought, a classical and critical subject. After all, I had planned to go to Carstairs next. Had I known about the closed bridge, I probably would never have travelled to this pretty parish. But since I was there, I found my view, a rainbow appeared, and the evening sun shone on Carstairs, Carnwarth, and the Clyde’s onward path to Lanark.

Attractions: Crawford Castle, an atmospheric ruin, is a good detour from the M74; Tinto Hill Tearoom is a welcome spot for lunch at the base of the hill; Quothquan Law is a quicker alternative; Carmichael Estate farm shop is well-stocked and has a small museum; The Bistro does light lunches and main meals; Pettinain has great views, and the house of Westraw is worth the short walk from the village to see.