The history of the the discovery of world's largest Ni-Cu-PGM deposits of Norilsk-Talnakh is revised. The 1866 prospecting and geographic expedition of Innokenty Lopatin and Friedrich Schmidt, studied the lowest Yenissei territories, and collected information and mineralogical samples (chalcopyrite from 'copper slates') proving by this the presence of a copper ore deposit in the Norilsk mountains. The deposit was developed by at least two adits since 1865 and was managed by brothers Pyotr and Cyprian Sotnikov from the settlement of Dudino (now Dudinka). This information was documented in the diaries by I. Lopatin and was reported by F. Schmidt in transactions of the Saint Petersburg Academy of Sciences. After the 're-discovery' of the deposit in the 20th century the followers have ignored, omitted and incorrectly cited the information published by Friedrich Schmidt in 1869 and 1872, as well as its republishing made by Vladimir Obrutchev in 1917. The real sequence of events resulting in the discovery of Norilsk deposits has to be rewritten. In memoriam of Sergey Gorbunov (1952-2021), archaeologist, traveler, Sakhalin history specialist