The information below has been put together by long time Challenger and vetter Colin Crawford, who has a quite extraordinary knowledge of the Scottish Highlands.
These notes are intended, in the main, for Challengers new to Scotland, though home based participants might find some useful information. I will offer a guide to the sorts of underfoot conditions you might expect, which are many and varied. Scotland enjoys a maritime climate with prevailing weather arriving from the west, so conditions tend to change gradually as you progress eastwards on your crossing. In general, terrain in the west is rougher and wetter but this isn’t an absolute rule and you can encounter challenging conditions wherever you may be.
I’ll start with the easiest walking and work towards the most difficult. I’d better add that much of the difficult stuff is entirely avoidable should you opt to stick to well-used paths and routes. If you read Challenge blogs or other trip reports it will quickly become apparent that there are a number of favoured itineraries which attract Challengers year after year. It would be a mistake to assume that these popular routes always represent problem-free going. Popular routes like the Lairig Ghru, Jock’s Road, Mount Keen and Loch Brandy would be no-one’s idea of an afternoon stroll. Take it as a loose principle though that if it’s considered as a ‘trade route’, a section is likely to offer a path or relatively straightforward walking.
Roads
Let’s begin with the most obvious features shown on the map. You could achieve a crossing entirely on tarmac, possibly a very fast and problem-free one, but I’d suggest that it wouldn’t be much fun. Only in towns are you likely to find pavements (sidewalks, footways) and verges can be scanty or non-existent. You could be sharing your route with heavy traffic and the stress on your pampered feet could be severe. I don’t often suffer from blisters but when I do, there’s usually a strong correlation between their severity and long spells of walking on tarmac. Many Challengers would agree with me in regarding long road sections as the antithesis of a good Challenge route. Having said that, some degree of road walking is probably inevitable in order to link up paths. Try to minimise it as far as possible, though sometimes you just have to shrug and accept a short section of purgatory.
Clearly, busy trunk roads are best avoided. In the west, particularly, it can be tempting to use red or green A roads when the map suggests few other options. An example here would be the A830 eastwards from Lochailort, where other possibilities can seem fairly challenging. I’ve vetted quite a few crossings where this has been proposed and I well understand the reasoning. Personally, I wouldn’t consider this to be an entirely safe choice, given the presence of thundering trucks appearing around blind bends and over summits. And enjoyment would be non-existent.
Minor roads are much better and can be welcome as an easy finish after a tough day. Light traffic and a firm surface can be a good combination, though you can have too much of a good thing and I find that even quiet roads become tedious after a while. It’s worth mentioning that on your final day, perhaps the final two, it may be impossible to avoid the roads. So make sure you select quiet ones (shown in yellow on the map). Most of us regard this final section as a necessary trudge and few would see it as a highlight of their crossing. A quick word on ‘white roads’ on the map. These can also be very useful if they’re available, but technically they’re regarded as private and you do run the risk, probably small, of a confrontation with a landowner. Discretion is the watchword here.
Tracks
Any route shown on OS maps with double-dashed lines will be a track of some sort. The quality can vary significantly, from well engineered dirt roads to rutted cart tracks. Tracks in forests are likely to be of higher quality, those in remote country may well have a much rougher surface. The maps don’t distinguish, alas and you may even find that the supposedly clear highway has deteriorated to nothing due to lack of use. Remote tracks are also less likely to be subject to maintenance, so puddles and erosion can be common. On newer tracks, which seem to increase by the year, you may struggle on stony surfaces – what’s good for vehicles isn’t always comfortable for feet and ankles. All that said though, it’s a moderately safe bet that a track on the map will represent tolerable and fast going.
Paths
In all likelihood, much of your crossing will be on paths of some sort, shown on the maps as a single dashed line. They vary enormously, from well maintained and waymarked routes to muddy trenches or stony horrors. Scotland has only a few National Trails and a small number of publicised routes so, for the most part, it is probably best to assume that paths will not be subject to regular maintenance. The Highlands have networks of old stalkers’ paths, constructed in the 19th and early 20th century, but many are now only used by walkers and receive little attention. On occasion, the map may suggest more of a route than you’ll find on the ground. It’s safe to expect that through routes between glens and paths to popular hills will exist; otherwise, exercise a degree of caution. Older maps can be suspect, hinting at paths which have long vanished into the heather.
You’ll find a distinction between constructed paths and what might be called ‘evolved’ ones. The latter are there because sufficient folk have wandered that way and a path has been trodden out. Most hill paths will be of this order, though the most popular ones have often been improved.
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And now for the off-piste stuff. You may never experience the following should you stick to popular routes but if you’re feeling lucky . . . .
Grass
In the Highlands, grass on the open hill is mostly coarse, rough to walk through but usually quite bearable underfoot. It can be much more lush in sheltered glens, becoming longer and harder to negotiate. And the longer it stretches, the more difficult it is to see where your feet will fall and the more welcoming a haven it becomes for nasties like ticks. Grazed fields and smooth lawns are scarce indeed.
On steep hillsides, smooth grass can be potentially perilous, especially when wet. Resist the urge to lope down easy looking slopes, otherwise you may find yourself in need of the ice axe which you won’t be carrying. On occasion, I’ve found my speed slowing to a crawl as I ease gingerly down such slippery chutes.
Tussocks can be an utter pain, when the grass grows in tight clumps with deep holes between. It’s not uncommon for the holes to be flooded, so you choose between sodden feet or teetering precariously on wobbling and uncertain purchase.
Bog
The acid soil in the Highlands is predominantly peat. On cols and often on hill tops in the east, vegetation recedes and you’re faced with naked black expanses of the stuff, its consistency entirely dependent on the weather over the preceding days. When dry, peat can be a delightful surface to stroll over, firm yet springy, very welcome after any period on rougher grass. Alas, the opposite applies when it’s wet (its default condition); ploughing through a stretch of semi-liquid black goo is no-one’s idea of fun and your footwear becomes caked in heavy, cloying detritus.
Peat often presents itself as hags and groughs, essentially a series of ridges and eroded channels. The channels can help if they coincide with your intended course but, all too often, they cut across the direction of travel and involve you in a series of tiring and dispiriting switchbacks. Progress through a labyrinth of peat hags and groughs can be exceedingly slow.
Marsh
Scotland gets a lot of rain so it should be no surprise that the ground can often be very wet underfoot. Extensive areas of low-lying flats, in river valleys or on broad cols are the worst offenders but you can find marshy sections even on areas of high ground. It’s usually possible to edge around them, but sometimes there’s little choice than to wade through, at the obvious cost of wet feet. Most of the time flooded terrain is evident enough but it can take you by surprise. Look out for patches of lurid green sphagnum moss, tempting when you first encounter it but a dead giveaway once you’ve experienced its horrors.
A curiosity sometimes met is the phenomenon of floating bog, where a firm surface exists as a crust over underlying liquid. You’ll only know about it when you’ve taken a few steps and had the unsettling feeling of the ground wobbling beneath you. Don’t be too concerned. I’ve never yet penetrated the thick crust and as long as you reverse your steps there should be no danger. The Hound of the Baskervilles is a good story but true Grimpen Mires are rare indeed.
Spongy ground
The prevailing climate means that vegetation grows lushly and, unless you’re on rock, the ground will usually give to an extent underfoot. This can reach extremes where grass grows thickly or where mossy tussocks prevail. Spongy ground is perhaps one of the most tiring surfaces to walk on; you’re never sure how deep your feet will sink and the effort of compensating and lifting your limbs up from unexpected plunges can be utterly draining. This isn’t just a feature of the glens. Untracked high ground, especially in the eastern hills, can be equally subject to this hindrance.
Watercourses
Water is very much a feature of Scotland’s landscape from small tumbling streams ( known as burns) to substantial rivers and lakes (known in Scotland as lochs). Where paths or tracks cross mountain streams don’t expect to find a bridge. In normal conditions crossing these shouldn’t cause problems other than the occasional wet foot. However water levels can rise quickly after heavy rain and in spate conditions crossing even small burn safely can become difficult and at times impossible necessitating long diversions. Every year bridges are lost in winter storms so you may find that bridges marked on the map are unsafe or missing altogether.
Heather
This all-pervading plant is very much a symbol of Scotland and is very beautiful when it comes into purple flower late in the summer. You won’t have that joy in May but you’ll certainly not miss the flowerless shrub. It occurs all over Scotland but is more prevalent in the east, where managed grouse moors are much in evidence.
There are three aspects to heather. Most benignly, it grows on top of hills as a soft carpet and can make high-level strolls a true delight; dwarf heather is one of my favourite walking surfaces. Alas, at lower levels, unconstrained by wind or altitude, it can grow to monstrous proportions. In places, you can be wading through cloying vegetation above your knees. Needless to say, it offers a lot of resistance as you force your way through. Lastly, in the managed areas, ‘muirburn’ is commonly carried out by estates, where old plant cover is burned off in order to encourage new growth. You‘re unlikely to experience the burning itself but you may come across the aftermath; charred ground and protruding heather stalks. If you’ve suffered a period of struggle through the deep living variety, the apparently open areas may seem like a relief. However, the burnt stalks are tough and very sharp, still capable of impeding your progress and tearing your clothing.
Oh and one other thing. Heather is home to these delightful little arachnids we know as ticks, lying in ambush for any tempting bare flesh on display.
Bog myrtle
A less common plant than heather, but it can grow in tandem with it. It’s more robust and is an additional obstacle when you’re facing a heather thrash. Extract of bog myrtle is sometimes marketed as a midge repellent. Don’t be fooled.
Gorse
Gorse is a spiky, prickly shrub which can cover large areas of hillside, particularly in the east, instantly recognisible by its livid yellow and pungent flowers. It can reach two metres in height and clusters together in impenetrable thickets. Don’t even think of forcing a way through, the only course being a change of course.
Bracken
Truly dreadful stuff, a ferny plant which in its season can grow over head height and carpets many hillsides. Consider yourself fortunate that Challenge time is before its peak flourishing; most of the growth which you’ll encounter will be harmless new fronds. You may, however, be less appreciative of the detritus from last year, where dead brown fronds lie as a deep pile carpet on the ground. And, particularly in woodland, even the dead stuff can still be upstanding to a degree. If you’re really unlucky, it’ll be accompanied by thorny briar.
Rhododendron
One of those dubious imports for which we have to thank rich travellers of past centuries. Originally Himalayan, it thrives in the acid soil of Scotland and has run rampant in areas where it has escaped the private estates in which it was nurtured. Rhodie thickets are like gorse, less prickly but utterly impenetrable. Retreat is the only option.
Commercial forestry
Conifer plantations are entirely manmade and are often disparagingly referred to as ‘pole factories’, or ‘trees on parade’. Monocultural, claustrophobic and largely lifeless within their confines, they are not pretty places but it’s likely that you’ll pass through at least one such forest on your crossing. They’re unlikely to cause problems if you keep to the mapped tracks and paths but, should you attempt a short cut, its success will depend on the maturity of the trees or having sufficiently large-scale maps. Mature forests usually have plenty of space between the trees, younger ones will have spiky branches at low level and will demand an unpleasant thrash. The 1:25,000 scale maps show firebreaks (open areas between the trees) but there is no guarantee that they will represent easy walking, being subject to lush growth of vegetation or occasional fallen trees. These forests have trees with shallow roots and they’re all too prone to keel over in strong winds. ‘Windthrow’ can be a very demanding obstacle.
When these forests are felled, an additional hazard comes into play. Large areas will be harvested, leaving an appalling no-man’s-land of tree stumps and ‘brash’ (dead limbs and branches). It can be crossed but is prime terrain for a broken ankle. Even on forest roads, passing through a vast area of felled plantation is distinctly unpleasant, as you gaze over scenes of ugly devastation.
Broadleaved woodland
Much better, you’ll feel and largely, you’d be correct. Natural woodland is usually attractive and pleasant to wander through. Yet similar warnings apply should you go off-piste from tracks or paths. Vegetation in unfrequented woodland can be lush indeed.
Other plants
Just to mop up, the iconic Scottish thistle appears from time to time and as long as you don’t make contact with their prickles, they won’t cause you problems. Be aware though that they have a habit of leaving tiny spines embedded within your skin if you brush against them. These can be very difficult to remove and painful until you do so.
Nettles are prone to grow in large clumps and can sting even through your clothing. The discomfort is fleeting though and they’re usually easy to avoid. The farmland in the east is probably where you’ll encounter them most.
Broom is often mistaken for gorse, of a similar size, sporting yellow flowers and forming close grown thickets. It has no prickles though, so is entirely benign.
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The following factors will only apply if you choose to cover any high ground, so if your Challenge route is entirely low level, you can safely ignore them.
Rock
High in the hills, the bones of the landscape poke through the softer soil. Mostly, rock is wonderful to walk over, representing firm and fast going, the very best of hillwalking. There are two situations where that can change. Firstly, and fairly obviously, rock has a habit of tilting towards the vertical. If you enjoy such games, scrambling up a steep rocky ridge will constitute one of the highlights of your day; if not, you may wish to seek out hills without such difficulties. Carrying a heavy pack is a factor too. I have several times climbed or descended a very steep gully on the Munro An Stuc in the Ben Lawers range. It never caused me any problems until I faced the descent on the Challenge, toting 11kg on my back. I became all too aware of the drop in front and of the pack’s weight unbalancing me.
Rock can be a wholly different prospect when it’s wet. Some rock – granite, sandstone, the famous Skye gabbro – retains a degree of friction when wet. Other types – basalt, schist, slate – become skating rinks. If, like me, you’re no geologist, it can be difficult to tell them apart. I’m always very cagey when walking on wet rock until I’ve gauged its level of friction. Any rock with a coating of ice will clearly be very hazardous indeed.
Boulder fields
The rock on Scottish hills isn’t always stable. On many hills, you’ll experience large boulder fields, which can be set at a steep angle or scattered along a summit ridge or plateau. The popular Munro Schiehallion has a kilometre of loose boulders along its summit ridge. Boulders can vary from small stones to huge blocks and you can’t assume that the latter will necessarily be more stable than the former . Care is always required on such terrain and progress will be slow. And once again, being top heavy with a backpack hardly helps.
There are several passes too with boulder fields. The summit of the Lairig Ghru is one such. Another is the nearby Chalamain Gap, where a slip or a wobble could have serious consequences.
Snow and ice
It’s never possible to predict how much snow will remain on the hills in May but the highest hills are always likely to have significant deposits. The Cairngorms have a habit of retaining a great deal of snow after a hard winter. I won’t dwell on this subject, on the assumption that anyone considering a high-level traverse when snow is present will have the skills and experience to cope. If in doubt, the maxim is to stay well clear.
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And that’s about it, I think. Have I put you off? I do hope not. In all probability your crossing won’t involve many of the torments described and you’ll sail along problem free. And if you do opt to be even mildly adventurous and extend your comfort zone a little, I would hope that you’ll have some idea of what to expect. Remember, when you’re toiling in difficult circumstances, one of the best quotes I ever heard about hillwalking; that the worst day on the hill is still better than the best day in the office.
Colin Crawford
TGO Challenge Route VetterNotes on Scotland’s Terrain