Here is a sketch map, "The Railways of Derbyshire", from an early twentieth century guide^[1] and shows the date it was drawn as 1903 (see corner, bottom right). The map,which is just inside the guide's front cover, is in two halves and is described by the author, J. Charles Cox, as the Index map. The way the volume is glued does not, unfortunately, allow the book to be totally flat when scanned.

It is interesting to see just how many railway lines criss-crossed the county before the first war. Up until the Beeching years, when many lines that didn't pay their way were scrapped, people could travel from Matlock and Matlock Bath, up through Rowsley, and then on to Miller's Dale, Chinley and New Mills before carrying on to Manchester Central station. In the west of the county the train would take vistors from Ashbourne and all points south up to Tissington to see the Well Dressings.

Cox wrote^[1]:

"Derbyshire was one of the first counties to use iron railways to ease transit. The very earliest use, above ground, was at Wingerworth ironstone pits, about the year 1788. ... In 1839 - 40 the Midland locomotive system of steam traffic came into being, the Company being formed from the Birmingham and Derby, the North Midland, and the Derby and Nottingham railways.

The county is now remarkably well supplied with railroads. The town of Derby is the great centre of the Midland railway system, and its lines branch out to most parts of the county. The Great Northern, the London and North Western, and the Great Central (succeeding to the Lancashire, Derbyshire and East Coast) railways all traverse certain parts of Derbyshire."

Elsewhere on this web site:
Derbyshire Railway Postcards. A selection of six from the early twentieth century series of cards.
Matlock Bath Station and High Tor.
Matlock Bath : Midland Express Passing Through the Station.
Stereographic Photo of Matlock Bath Station, 1860. A hold-to-light tissue stereographic photo, with an element of surprise.
Stereoview of Matlock Bath Station (2), Nineteenth Century.
High Tor & Railway Station, Matlock Bath, 1862.

References:

^[1] From: Cox, John Charles, (1915, 2nd edition, revised), "Derbyshire" - Illustrated by J. Charles Wall, Methuen & Co., London. First edition published in 1903.