The northern part of its route crossed wild and sparsely populated terrain, and the high summits on the line were challenging for the locomotives of the day.

[1] Interested parties in Inverness gave thought to getting a railway connection of their own, as they were aware of the commercial and social benefits.

However the topographical obstacle of the Monadhliath Mountains obstructed any route running directly southward, and it was obvious that for the time being, such a railway was impracticable.

They contented themselves with reaching Aberdeen, which at least would give them a connection to the south, albeit by a considerably roundabout route.

[2] Joseph Mitchell was an engineer based in Inverness, and his dynamic approach coupled with that of business interests in the Burgh, encouraged the development of a practical scheme to reach Aberdeen.

After much difficult negotiation, the Great North of Scotland Railway was formed and built a line from Aberdeen to Keith, opening to that place on 10 October 1856.

[6] From that date the I&AJR worked the Inverness and Nairn Railway, but for the time being the latter company retained its independent existence.

[8] The Inverness and Perth Junction Railway was formed by Act of Parliament on 22 July 1861, with share capital of £654,000.

[8] Despite the difficult terrain, there were relatively few major engineering works needed, although a large number of ordinary underbridges were required.

As guests of the SNER, the Inverness and Perth Junction Railway trains used the General station too.

Clearly the SCR had an effective monopoly, and exploited it fully in their usage charges, which were £10,000 in 1865 increasing annually.

c. cccxvii) authorised the Strathtay and Breadalbane Railway to build from the Inverness and Perth line at Ballinluig to Aberfeldy; it was givenroyal assent in 1846,[20] in anticipation of an early Inverness and Perth line, but that was not constructed, and the powers were suspended by Act of 10 June 1847.

The working of banking engines down the gradient after assisting trains up to the summits compounded line capacity difficulties, and it was time to improve matters.

The Highland Railway (Additional Powers) Act was passed on 6 August 1897 empowering the company to double the line from Stanley Junction to Aviemore.

[25] By 2 July 1900 doubling had been completed from Blair Atholl to the crossing loop at Dalnacardoch, and was through to Dalnaspidal by 13 May 1901.

In the meantime, it had been decided to carry the double track as far as the County March crossing loop, and this was reached on 10 June 1901.

[25] In time, the eastward sweep from Inverness to Aviemore was seen to be an unnecessary complication, particularly as increasing traffic volumes came from the Dingwall section.

Parliament was expected to be sympathetic to those proposals if the Highland Railway was not improving its line for the benefit of its own customers.

A goods service to Dallas Dhu distillery was continued to Forres East until 21 May 1967, and that short section of line was officially closed on 30 June 1967.

Claud Hamilton Ellis wrote a detailed description of the Dava route in the Railway Magazine, January 1934.