The Masham branch was a 7+3⁄4-mile (12.5 km) long North Eastern Railway built single track branch railway line that ran between a junction on the Harrogate to Northallerton line at Melmerby to Masham, North Yorkshire, via one intermediate station, Tanfield.

[1] After a number of abortive attempts to link the market town of Masham, Wensleydale, the branch line was authorised by an Act of Parliament in 1871 and construction started in 1873.

[2] The line was delayed in opening for a full year as the railway company could not agree terms for some of the land.

Masham had a goods yard directly next to the station platforms, but was also provided with a transhipment goods yard north of the station and across the Masham to Melmerby road (now the A6108 road) for the narrow gauge railway supplying the reservoir building further west.

The cause was later attributed to newly laid rail on a bed of ash (instead of being properly ballasted) that had buckled in unseasonably hot weather.