The A887 is essentially a link road through Glen Moriston from the A82 to the A87 for traffic travelling between Inverness and Kyle of Lochalsh and the Isle of Skye. Although a trunk route, traffic volumes are low and until surprisingly recently there was a short section of single track with passing places.
The road starts in the small village of Invermoriston near the shore of Loch Ness at a turning off the A82. Very soon the few houses are left behind and the road climbs away from the Great Glen. As it runs along the river bank, the road is generally very wide and quite straight. The scenery is good, although the mountains are not very high at this point and trees along the roadside screen some of the best views. The road winds up the valley, never wandering far from the almost invisible river, along a series of short straights and fast sweeping bends. One of these sweeping bends curves round the head of the Dundreggan Reservoir and its power station. 60 mph is certainly a comfortable speed for most of this section of the route.
After about six miles the road reaches the long straggly settlement of Dundreggan, with houses strung along the roadside for the next mile or so. The road does narrow somewhat, but has been widened so it is no longer single track, although there are a couple of pinch points to watch, especially when large vehicles are approaching. Beyond Dundreggan, the road curves round to the south to cross to the other side of the River Moriston, which it has been following since the start. There is a turning on the right just before the bridge, which is a dead end unclassified road to the few small hamlets further up the glen, and another to the left just after the bridge to a couple of farms.
After the bridge the carriageway widens out again quite quickly and flows westwards along a series of long fast straights. The road has been thoroughly realigned, and the few properties are now bypassed and hidden behind trees. The south side of the glen is, however, almost deserted compared to the north side of the river. There is a much longer realignment at Ceannacroc, which bypasses two older Bridges, before the A887 sweeps over the river for the last mile to the A87 junction at Bunloyne. This is a TOTSO, with the A87 joining from the left with traffic from the South for the Isle of Skye. Very little traffic turns between the A887 and A87 south, unless the A82 is closed, when this route becomes the diversion.
The OS 7th Series map shows the original A887 and the new A82 under construction above the water line of the new reservoir
The route of the A887 was originally built by Thomas Telford from Invermoriston to Achlain in the early 1800s as part of his commission on Highland Roads and Bridges. At Achlain, he followed the Old Military Road, built by Major Caulfeild in the 1750s as far Ceannacroc, where it wandered off up the hill, so Telford again built a new section of road west to Cluanie, albeit using a couple of further sections of the older route. This road was then numbered as the B852 in 1922, but was soon upgraded as it was the main route from Inverness to Kyle and Skye. Until the 1950s, the road continued west from Bunloyne Junction along the length of Loch Cluanie to Cluanie Inn. However, as the construction of the Loch Loyne reservoir flooded the original route of the A87 in the 1950s, a new road was built from Invergarry to Bun Loyne. It then took over the original western section of the A887 to the Cluanie Inn. This section is also new-build as Loch Cluanie was dammed around the same time and much of the old alignment of the road was flooded.
As the A887 has been thoroughly rebuilt over the years, much of the old road lies abandoned nearby. East of Torgoyle Bridge, the improvements are largely online, so other than a few laybys, and evidence of bends being reprofiled, there are no long stretches of old road to explore. Dundreggan Dam caused a short new section of road to be built, as the old road has been flooded. beyond Torgoyle Bridge, the old sinuous road has been replaced with long straights, leaving a series of loops on alternate sides of the road past the Fish Farm site and continuing most of the way to Achlain. Some of these loops can still be walked part way, but some have become overgrown and aren't really passable even on foot.
Just before Achalin, a footpath sign points up hill for the old military road route, and past the farm a much longer loop survives to the north of the new road. The next mile is largely online, before a long layby on the right shows the old road line again. The next two bends have both been reprofiled, and then there is apparently simultaneous evidence of old road line on both sides of the modern road. The path marked by the OS to the south is generally thought to be the line of the military road, while the loop in the trees to the north seems to be a modern forest road. Soon after this, the old road forks right into the trees for the long bypassed approach to Ceannacroc Bridge. Here, the old military road disappears off up the glen and over the hill, while the A887 sticks more closely to Telfords line through to Bunloyne.
The section of road past Loch Cluanie built by Telford is now largely submerged, although stretches of tarmac and bridges do appear when the water level drops. However, there is also regular evidence of an old road, mostly on the uphill side of the current A87. This seems to have been the original new road built in the 1950s when the glen was dammed, and some of it may have briefly been numbered as the A887 before the A87 was re-routed. Curiously, although the new A87 road from Glen Garry was all built as S2, the section along Loch Cluanie was originally only single track.