The
etymology of the term "blue spur" not well known. The gold diggers of the 1860s gold rush went after the gold "on the spur (of the moment)", i.e. in a great hurry/rush.
Alluvial gold may often be found close to a layer of blueish
clay. Miners frequently talk about
mining down to the "blue clay", thus a "blue spur" could somehow elucidate the hasty process of digging for the gold pursuing a blueish layer of clay. Other potential meanings could refer to a blueish colour of mountains ("blue mountains") as it can be spotted in certain light at distant mountains at this location, combined with the geological meaning of a spur, i.e., a secondary mountain ridge. Besides these gold rush-related connotations there is a "blue spur flower" (
Plectranthus ciliatus), and the "blue spur" in coats of arms. ==References==