Hatter Graben Nevada

The Hatter Graben vein system provides the next leg of growth at Hollister. The Hollister Mine (Ivanhoe Mining District), which Hecla acquired in July 2018, is located in Elko County, approximately 130 km (~80 mi.) northeast of the town of Winnemucca, Nevada and 29 km (~18 mi.) southeast of the Midas Mine.

Map - Hatter Graben
Overview & History

This Hatter Graben vein system is located approximately 2,500 feet east of the Hollister Mine’s underground development and has been down dropped approximately 800 feet lower than the current Hollister Mine resource. The system of mineralized veins have a known vertical extent of 1,400 feet and strike length of 2,000 feet. This East-West trending zone is open along strike to the east and west and at depth. There is good exploration potential with historic high-grade intersections occurring up to 4000 feet along strike to the east of the know vein zone.


Gold and silver mineralization is dominantly in the Ordovician quartzites, siltites and argillites. Higher grades are associated with banded quartz veins from inches to feet in width and extensive zones of quartz vein stockwork and quartz matrix breccias also contain significant mineralization. Significant mineralized drillhole intercepts include 7.8 Au oz/ton over 1.4 feet, 1.77 AU oz/ton over 2.1 feet, 1.4 Au oz/ton over 2.3 feet, 0.54 Au oz/t over 7.8 feet, and 0.47 Au oz/ton over 12.5 feet.


In 2021, at Hollister, the development drift advanced at the Hatter Graben exploration area allowing completion of the first drillhole that targeted and confirmed multiple zones of banded quartz veins and veinlets south of the existing resource. In 2022, exploration of the Hatter Graben is expected with further development of the decline setting up exploration drilling to upgrade a portion of the current Hatter Graben resource and explore additional Hatter Graben veins both to the south and east of the current resource area. To date, 2,400 feet of development has been completed along with the necessary ventilation and dewatering infrastructure, additional footage is planned through the first half of 2022.