After Robert Blackmore, one of the party with R.H. Lee in 1895, on an exploratory trip to the Big Bend country. See 1895 field book 176A/1895, ph 3, Lillooet Land District.
The name “Blackmore” was first suggested for a nearby creek, already well known as Bulldog Creek (file C.1.53). “Blackmore” re-positioned to this feature, to retain the name in the immediate vicinity