The Imsogrek mountains are honeycombed with mine shafts, tunnels, and cavern complexes. In the Horgon Era it was mined by Râpha-Sûn, and after this it was heavily exploited by the Tinnanguth Empire. They followed copper veins so rich that Imsogrek Copper could be found thousands of miles east in young settlements like Ing-Serold. Before nationalist interests set-in, they stamped it with a mountain, and called these copper coins Imsogreks.
Until the Year 400, Imsogrek mining was slow and often costly. The miners were mostly Sussgurd, now free people in Tinnanguth. Some were descendants of those that had worked the mines as slaves under Abâthigûr. In the fifth century, this began to change with Tinnanguth advances in conjuration magic. Thereafter, the work became the province of those very capable at digging, races like the dao and earth elementals were brought in do the dirty work.
After the Dao Civil War, Tinnanguth's former slaves had become upper Karnegmoth's new masters. By then, the mountains as far as Glascis had been fully exploited. This left behind innumerable abandoned mines, tunnels, and former living areas. Today, some of these areas are bases for Greenland guerrilla units.