The early 80's saw the rise in both standards and popularity of mixed climbing on Cairngorm Granite but it would be the mid 90's before this really caught on to Nevis Andesite (with the glaring exception of Centurion in the uber winter of 1986). Fashions in climbing come and go but the drive for hard mixed climbing on both of these conducive rock types, on either side of the country, continues with routes like The Hurting (Cairngorms) and The Secret (Nevis) representing the current high water mark in Scottish mixed climbing standards.

Whilst technological advances in hardware had a role to play in increasing difficulty it seems a greater factor was the personal drive and talent of a number of individuals. From Naismith to Macleod there are a number of 'star performers' who have clearly pushed the boundaries of difficulty and inspired future generations to take up the mantle. Collie, Naismith, Raeburn, Smith, Fowler, Richardson and Turner to name but a few on the West. Patey, Cunnigham, Nisbet, Mullin and Macleod have all pushed the boundaries on the East. Kenny Spence should also get a mention here for his routes (Citadel and Centurion) that still stand out on both sides of the country.

By focusing purely on the current grading of the climbs endless important ascents are obviously missed (Smith and Holts first foray onto the mighty Orion Face in 1959 being a good example). It is interesting to note that many of the classic winter climbs are also not mentioned as slightly more obscure routes of the same grade were climbed first. For Example Observatory Buttress Direct pre-dates Zero, Point Five, Smiths and Orion as the first Nevis grade V in 1952.    

In terms of advancing pure technical difficulty Smith and Marshall's fantastic week of climbing in 1960 doesn't get mentioned either but must rank as one of the most significant periods in Scottish winter climbing history.

The first true ascent of Point Five Gully, Smith's Route, Orion Direct and others. A superb achievement and the high watermark of a style of winter climbing that would only be improved on with technological advances in hardware.

Clearly many other highly significant ascents were made away from these 2 areas, particularly in the mixed forging crucibles of Glen Coe and Lochnager. Of particular note are Tom Patey's winter Eagle Ridge (VI,6) in 1953 and Hamish MacInnes's fine winter ascent of Agag's Groove (VII,7), Glen Coe, in the same year.

In compiling the dates of these ascents (and all information is taken from the SMC climbing guides) there is one climb that stands out in terms of being way ahead of it's time; the hardest ice climb in the world and not repeated for 30 years!
    
The route is Green Gully (IV,3), Ben Nevis. Remarkably first climbed in 1906 by Harold Raeburn.

Later in the 50's Scottish mixed routes (like Eagle Ridge, Tower Face of the Comb and Agag's Groove) and ice climbs (Orion Face, Scorpion, Zero Gully) were again at the cutting edge of world winter climbing difficulty with only things like the N. Face of Les Droites (1959) being comparable.

No. 3 and 4 Buttress, Coire an Lochain, N. Cairngorms - A forging ground for hard new mixed routes over the last 50 years!
The Minus and Orion Faces high on Ben Nevis. A forging ground for hard, thin and serious ice and mixed routes over the last 50 years.     

Again in the 70's Alex Mcyntire & Nick Colton used skills learnt on the Scottish winter crags to 'snatch' the eponymous Alpine North Face Plum on the Grande Jorasses from under the noses of the local Guides. This was certainly the hardest ice climb in the Alps at the time - done by a Leeds Uni student and unemployed Manchester dosser, Brilliant!

International meets run by the BMC and based in the Highlands in the late 90's and early 21st C demonstrated that international winter climbers and alpinists were operating at a higher level than those in the Highlands. Without too much difficulty climbers like Janez Jeglic, Alex Huber, Marko Prezelj and Heinz Zak were able to turn up and climb the hardest routes of the day, but they loved it!
    
Aladdins Couloir (I). One of the first winter climbs in the Northern Cairngorms. By this time in the West Highlands numerous grade IV's had been climbed!
    
More recently climbers like Andy Turner, Guy Robertson, Ian Parnell and particularly Dave Macleod have contributed routes to both Ben Nevis and the Northern Cairngorms that bring winter climbing in the Scottish Highlands back onto the world stage not only in terms of difficulty but commitment and quality as well.

The melting pot of an increasing number of Brits being inspired by these routes; more and more of them taking to the gym and dry tooling facilities and still plenty of good, hard, unclimbed winter routes to be done means the future looks bright for Scottish Winter Climbing.

Postscript: Many thanks to Colin Wells for the following supplementary information regarding the Scottish winter routes described above in a British, never mind international, context. It seems the Lakeland winter pioneers were even quicker off the mark than Mr. Raeburn!...

...."it might be worth noting that although Raeburn's ascent of Green Gully was certainly advanced in a Scottish context, (and therefore, as you suggest, 'way ahead of its time' for Ben Nevis), much harder winter climbs (comparable to the standards being achieved in Scotland in the early 1950s) had been regularly ascended in the Lake District during the 1890s and the decade prior to the Great War. (It's perhaps especially worth noting the first ascent of a Grade V - Steep Gill - by Collie as early as 1891 for example; the first solo of a Grade IV , 4 by Jones, (Moss Gill) in 1893; and the first Grade VI climb in 1919 by Bower and party)

This research was first published 10 years ago and is also on the web at the following URL:

http://www.frcc.co.uk/rock/history/winter/winterclimbinglakes5-1.htm

It is clear from the very good documentary records available that the climbers operating in the Lakes in the Victorian and Edwardian periods (and also Wales, although this is not documented in the source cited) were climbing gullies and mixed routes that were technically considerably advanced from most of the equivalent Scottish ascents of the period.

Although this has been known for some time, it seems that it has been slow to penetrate climbers' consciousness in Scotland!"

Best wishes,
Colin