In 1958 in a major re-drawing of the region boundaries it gained those former LMS lines that lay in the present-day West and North Yorkshire.

The eastern section of the Trans-Pennine route, Hull to Leeds, also ran through this region, as did the Newcastle and Carlisle Railway.

The conurbations of Tyneside, Wearside and Teesside contained a high density of lines carrying not only suburban passenger traffic but also large volumes of freight generated by the coal, steel and chemical industries of the area.

This was a rare, possibly unique, example of a locomotive class which was built, substantially unchanged, under pre-grouping, post-grouping and British Railways administration.

Former LMS locomotive types also began to work in the region from the late 1950s onwards and became a familiar sight on the Stainmore line and on the coastal passenger routes in Yorkshire.

From 1961 it received six of the 22 production Deltic diesel-electric locomotives which enabled the acceleration of many of the East Coast Main Line passenger services between King's Cross and Scotland.