Gumfields
Most of the gumfields were in Northland, Coromandel and Auckland, the site of the original kauri forests. Initially, the gum was readily accessible, commonly found lying on the ground. Captain Cook reported the presence of resinous lumps on the beach at Mercury Bay, Coromandel, in 1769, although he suspected it came from the mangroves, and missionary Samuel Marsden spoke of their presence in Northland in 1819.
By 1850, most of the surface-lying gum had been picked up, and people began digging for it. The hillsides yielded shallow-buried gum (about 1 m), but in the swamps and beaches, it was buried much further down (4 m or below).
Read more about this topic: Kauri Gum