This article is about the former B873 from Latheron to Georgemas Junction.
For the current B873 through Strathnaver, see B873.
The 1922 Road Lists describe the B873 as Latheron - Thurso
The road ran from coast to coast in Caithness and connected the A88 to itself; that road took a longer, presumably easier, route to the east via Wick and Castletown.
By 1932 the road had ceased to exist. Firstly the A88 had been rerouted, taking over the B873 north of Georgemas Junction. The remainder of the road became the A895. It is not known, however, which of these changes came first: whether it was the B873 of A895 that was truncated when the A88 was rerouted.
What is known is that the A882 took over the A88 in this area in 1935; the A9 which took over the A88 as far as Wick then left it to go to John O' Groats. This was the situation until the 1990s when the A9 was rerouted to Thurso instead, taking over the entire of the ex-B873 in the process.