Hollister Nevada

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 - Hollister
Overview & History

The Hollister Mine is a large, very well preserved low-sulfidation, epithermal gold-silver deposit associated with mid-Miocene bimodal volcanism of the NNR. Over 115,000 ounces of volcanic-hosted, low-grade gold were extracted from 2 open pits. Later drilling led to the discovery of blind, high-grade veins in the Valmy Formation, Paleozoic basement rocks, which have produced >450,000 ounces of gold and >2.5 million ounces of silver from ore averaging ~34 g/t Au (1.00 opt) and 200 g/t Ag (5.83 opt) from cut-and-fill and longhole stoping since 2007. Typical epithermal vein textures are displayed at Hollister, most commonly massive, banded, bladed quartz, and vein breccias. Other features spatially related to the highest grades include the presence of banded quartz, bladed quartz, and alunite.

Geology

The mine is located along the Northern Nevada Rift (NNR) which is a major, north-northwest to south-southeast trending structural feature that that extends for at least 300 miles, from south-central Nevada to the Oregon-Nevada border. This is on trend with the north-western end of the Carlin Trend, which is approximately 5 miles wide and 40 miles long. Mineralization is related to the Miocene period of magmatic activity associated with the NNR while gold mineralization on the Carling Trend has been dated to late Eocene/early Oligocene magmatism.

Epithermal disseminated gold mineralization is hosted in volcanic tuffaceous units, andesites, and the Ordovician Vinini Formation. High-grade gold and silver mineralization is hosted as banded quartz veins in a group of near-vertical faults and fissures that trend west-northwest to east-west. The amount of displacement across these faults is small and their strike continuity varies between one hundred to several thousand feet. Primary lithologies in the area have been strongly altered by hydrothermal fluids with large areas of chalcedonic replacement bodies at the paleo water table in addition to sinter deposits.

Production – Nevada Operations
(years ended December 31)
2018
Silver (ounces) 172,301
Gold (ounces) 32,887
 
Historical  
2017
Silver (ounces) 47,305
Gold (ounces) 6,751
 
Resources

Information with respect to measured, indicated and inferred resources is set forth below.

 

Mineral Resources (As of December 31, 2019 unless otherwise noted)          
 Tons Ag Au Ag Au
(000) (oz/ton) (oz/ton) (000 oz) (000 oz)
Measured (1,2) 103 3.6 0.57 376 59
Indicated (1,2) 182 2.2 0.58 410 105
Total M&I Resources 285 2.8 0.58 786 164
Inferred Resources (1,2,3) 466 2.7 0.40 1,247 185
 
(footnotes)

(1) Mineral resources are based on $1500 gold, $21 silver, $1.15 lead, $1.35 zinc and $3.00 copper, unless otherwise stated.  Cut-off grades are as above unless otherwise stated.

(2) Hollister mineral resources are reported at a gold equivalent cut-off grade of 0.294 oz/ton. The minimum mining width is defined as four feet or the vein true thickness plus two feet, whichever is greater.

(3) Inferred resources for the Hatter Project at the Hollister Mine calculated using recoveries for gold and silver of 82.7% and 71.8% and an Au equivalent cut-off grade of 0.294 oz/ton.

Reporting requirements in the United States for disclosure of mineral properties are governed by the SEC and included in the SEC’s Securities Act Industry Guide 7, entitled “Description of Property by Issuers Engaged or to be Engaged in Significant Mining Operations” (Guide 7). However, the Company is also a “reporting issuer” under Canadian securities laws, which require estimates of mineral resources and reserves to be prepared in accordance with Canadian National Instrument 43-101 (NI 43-101). NI 43-101 requires all disclosure of estimates of potential mineral resources and reserves to be disclosed in accordance with its requirements. Such Canadian information is being included here to satisfy the Company’s “public disclosure” obligations under Regulation FD of the SEC and to provide U.S. holders with ready access to information publicly available in Canada.

Reporting requirements in the United States for disclosure of mineral properties under Guide 7 and the requirements in Canada under NI 43-101 standards are substantially different. This website contains a summary of certain estimates of the Company, not only of proven and probable reserves within the meaning of Guide 7, which requires the preparation of a “final” or “bankable” feasibility study demonstrating the economic feasibility of mining and processing the mineralization using the three-year historical average price for any reserve or cash flow analysis to designate reserves and that the primary environmental analysis or report be filed with the appropriate governmental authority, but also of mineral resource and mineral reserve estimates estimated in accordance with the definitional standards of the Canadian Institute of Mining, Metallurgy and Petroleum referred to in NI 43-101. The terms “measured resources”, “indicated resources,” and “inferred resources” are Canadian mining terms as defined in accordance with NI 43-101. These terms are not defined under Guide 7 and are not normally permitted to be used in reports and registration statements filed with the SEC in the United States, except where required to be disclosed by foreign law. The term “resource” does not equate to the term “reserve”. Under Guide 7, the material described herein as “indicated resources” and “measured resources” would be characterized as “mineralized material” and is permitted to be disclosed in tonnage and grade only, not ounces. The category of “inferred resources” is not recognized by Guide 7. Investors are cautioned not to assume that any part or all of the mineral deposits in such categories will ever be converted into proven or probable reserves. “Resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of such a “resource” will ever be upgraded to a higher category or will ever be economically extracted. Investors are cautioned not to assume that all or any part of a “resource” exists or is economically or legally mineable. Investors are also especially cautioned that the mere fact that such resources may be referred to in ounces of silver and/or gold, rather than in tons of mineralization and grades of silver and/or gold estimated per ton, is not an indication that such material will ever result in mined ore which is processed into commercial silver or gold.


2019 Reserves & Resources PDF

Exploration

There are currently no mineral reserves at Hollister.  At Hollister, measured and indicated resources are 164,300 ounces of gold and 785,800 ounces of silver and inferred resources are 184,800 ounces of gold and 1.25 million ounces of silver.

Hatter Graben

The Hatter Graben vein system provides the next leg of growth at Hollister. This vein system is located approximately 2,500 feet east of the Mine’s underground development and has been down dropped approximately 800 feet lower than the current 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 and mineralization is strengthening in the East as historic high-grade intersections occur up to 4000 feet along strike to the east.

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.