Altnaharra Bridge crosses the River Mudale immediately to the north of the tiny village at the heart of the vast, empty county of Sutherland. The bridge was built by Thomas Telford as part of his commission on Highland Roads and Bridges. The bridge is a solid stone structure of 3 arches, with the central arch being slightly larger than the other two, and is believed to have been built in 1815, with Telford's road from Bonar Bridge to Tongue completed 4 years later.
Junction
To the north of the bridge is a crossroads, where the B873 terminates on the A836. The fourth arm of the junction, facing the B873 is a minor road, which leads back to the north coast and the A838 at Hope. The junction is a simple give-way junction, with all four arms being single track.