This is more or less the route featured in both Adrian Hendroffs Donegal/Sligo/Leitrim guide and Helen Fairbairns "Irelands Best Walks" and as such its pedigree as a fine introduction to the curious charms of the Bluestacks is fairly well established. I did it on a stolenSaturday afternoon with cloudy but clear conditions towards the end of what was an apocalyptically damp summer even by Irish standards.
The track-thats-really-a-road mentioned by both authors had a Road Closed sign at the junction, so I elected to walk up it rather than drive: this adds about 2km with minimal ascent over tarmac to the walk. Once across the Grey Mares Tail stream (easily crossed, so I suspect this is only an issue during rather than after heavy rain) I discovered that a manky great new bulldozed track has appeared in this otherwise rather wild valley. Through gritted teeth I followed it alongside the river to where it forks, taking the left hand branch here. (It should be noted that the Second Series OSI map of this area can charitably be described as casual and approximate when it comes to representing watercourses hereabouts; some tributary streams are represented as being of almost Amazonian dimensions when theyre barely noticeable on the ground). The track winds steeply uphill to an end just shy of the 500m contour, but continuing in this direction soon deposits you on the summit slopes of Lavagh More. The northerly top is higher, and it seems that the southerly one (point 668m on the map) doesnt have enough prominence for V-L status...about 12m I reckon.
In clear conditions the route onto Lavagh Beg was obvious, a descent that rolled and rollicked over grass and rock leading to a similar (but shorter) ascent. Once past the initial descent from this top, the way onto Binnasruell can be described as a cross-country trek oer moor and fen...I managed to avoid any proper watery immersions for my feet so it is possible, but it was a pretty mucky stretch if truth be told. A couple of surfaces seemed to vie for the honour of crowning the last summit, with each looking higher when viewed from the other (one of those). The slopes immediately south of the top become very steep rather quickly, and the descent is best accomplished by starting off in a more westerly direction and working your way around. I went a bit more directly than that, because I have all the patience of a starving tiger being presented with a slab of raw meat.