In 2006, International Tower Hill Mines Ltd., began work at the Livengood prospect (Klipfel, Carew, and Pennstrom, 2009). The prospect covers a northeast-trending area at least 2 by 3 kilometers in size near Money Knob and includes several smaller and older prospects including the Griffin, Lillian Creek, Ruth Creek, and Old Smoky. Individually these older prospects are now mainly of interest for their geological relevance to the large body of mineralization that International Tower Hill has defined and was studying and drilling in 2011 (Brechtel and others, 2011).

The Lillian Creek prospect (about 0.7 mile northwest of Money Knob) consists of narrow auriferous arsenopyrite-quartz-scorodite veins in and near a limonite-stained dike in altered and contorted graywacke-argillite country rocks. Samples of the veins contained 0.5 to 48 parts per million (ppm) gold (Foster, 1968). Joesting (1942), reported a mineralized zone in a cut bank that contains stibnite and traces of cinnabar and gold. The Ruth Creek prospect (about 0.4 mile northwest of Money Knob) consists of numerous, nearly vertical quartz veinlets striking S 20-60 E, that contain pyrite and arsenopyrite (Mertie, 1918). Some of these veins assayed up to 0.58 ounce of gold per ton. The veinlets are cut by calcite veins carrying some gold and sulfides (Mertie, 1918). Contiguous mineralized zones up to 36 inches wide are in altered dolomite-calcite-quartz-sulfide rock (Foster and Chapman, 1967).

The best known of the old prospects near Money Knob is the Old Smoky prospect, about 0.3 mile north of Money Knob. Trenching near the head of Olive Creek exposed narrow, northwest-trending auriferous arsenopyrite-quartz veins near the intersection of an altered, porphyritic, biotite-monzonite dike, with a potassium feldspar-porphyry dike (Foster, 1968). The mineralization is in shale, argillite, fine-grained sandstone, and pebbly conglomerate (Allegro, 1984; Athey, Szumigala, and others, 2004; Athey, Werdon, Newberry, and others, 2004; Athey, Werdon, Szumigala, and others, 2004; Athey and Craw, 2004). Narrow zones of thermal metamorphism are along sheared contacts between the sedimentary rocks and hypabyssal intrusive rocks.

Most of the intrusive rocks and some of the sedimentary host rocks at the Old Smoky prospect have experienced variable degrees of metasomatic hydrothermal alteration followed by lower-temperature supergene alteration (Allegro, 1984). Allegro described four types of hydrothermal alteration: 1) silicification, as partial to complete replacement of the host rock by a dense network of quartz veinlets generally localized along contacts between the intrusive and sedimentary rocks; 2) sericitization, as fine- to medium-grained white mica in selvages along quartz veins, as anastomosing sericite-opaque mineral veinlets, and as patchy to massive sericitic replacement of feldspar, ferromagnesian minerals and quartz; 3) deposition of trigonal nets of needle-like rutile often associated with secondary quartz and minor feldspar; and 4) epidote +/- sericite as a replacement of calcic plagioclase and ferromagnesian minerals resulting in massive aggregates, pseudomorphs, veins, and vug fillings of epidote commonly associated with sericite, opaque minerals, and quartz.

Since the mid-1970s a succession of companies have explored the area around Money Knob (Brechtel and others, 2011). Homestake Mining Company drilled 6 holes in 1976; Occidental Petroleum drilled 6 holes in 1981; Amax Exploration drilled 3 holes in 1991 and did surface geochemistry and sampling; Placer Dome drilled 9 holes in 1995 and 1996; and Cambior Inc. explored in 2001-2002.

In 2003, AngloGold Ashanti (USA) Exploration began work and drilled 12 holes. In 2006, International Tower Hill Mines Ltd. (ITH) acquired the property from AngloGold and began an aggressive exploration program that was ongoing as of August 2011. By late 2011, ITH had drilled 550 reverse-circulation holes and 94 core holes, covered the property with several geochemical surveys as well as by aerial and ground geophysical surveys, and collected and analyzed a multitude of samples. They have also commissioned a series of twelve, detailed, increasingly sophisticated 43-101 reports that describes the geology in detail, lays out development scenarios for the property, and for some years has quantified the resources of the property. The latest of these is by Brechtel and others (2011); the earlier ITH 43-101 reports that are largely superseded by it are included in the reference list. Almost all of the description that follows comes from those reports. As of late 2011, ITH had outlined a deposit that they propose to mine from a large open pit about 3,000 feet long and 1,500 feet wide.

The oldest rocks at the prospect are late Proterozoic to early Paleozoic basalt, mudstone, chert, dolomite, and limestone of the Amy Creek sequence. A Cambrian ophiolite sequence of mafic and ultramafic rocks is in thrust contact above the Amy Creek sequence. The ophiolitic rocks are overlain by Devonian shale, siltstone, conglomerate, and volcanic and volcaniclastic rocks; the Devonian rocks are the main host for the mineralization. The Devonian rocks are overthrust by more Cambrian ophiolitic rocks. All are intruded by 92 to 93 Ma (Cretaceous) monzonite, diorite, and syenite stocks, dikes, and sills that are considered to be genetically related to the mineralization. The host rocks are part of fold-thrust belt of Paleozoic and/or Cretaceous age and the complex thrust-fold architecture is apparently the key to the emplacement of the Cretaceous stocks, sills, and dikes, and forms the pathways for the mineralizing hydrothermal fluids.

The mineralization occurs in two styles: as multiphase quartz veins spread through the ore body, and as disseminated ore minerals. The disseminated low-grade mineralization is pervasive; many of the drill holes are mineralized for 50 percent or more of their length. The stages of mineralization from early to late are: 1) intrusion of feldspar porphyry dikes and sills; 2) arsenopyrite-pyrite-gold mineralization accompanied by biotite alteration; 3) arsenopyrite-pyrite-gold mineralization accompanied by albite-quartz alteration; 4) arsenopyrite-pyrite-gold mineralization accompanied by sericitic alteration; and 5) late stibnite-gold mineralization accompanied by propylitic alteration and the intrusion of late, biotite porphyry dikes and sills.

As of August, 2011, at a cutoff grade of 0.22 gram of gold per tonne, the Livengood deposit has a measured and indicated resource of 933 million tonnes with an average grade of 0.55 gram of gold per tonne (or 16.5 million ounces of gold). At the same cutoff, there is an additional inferred resource of 257 million tonnes with an average grade of 0.50 gram of gold per tonne. The estimation of a reserve was not possible at that time.

In October 24, 2016, International Tower Hill Mines Ltd. (ITH) released a prefeasibility study for its advanced-exploration-stage, Livengood gold project (Hardie and others, 2016). ITH’s initial, proposed optimized project configuration includes a conventional surface mine utilizing large-scale mining equipment in a blast/load/haul operation. Mill feed would be processed in an estimated 47,700 tonne-per-day comminution circuit consisting of primary and secondary crushing, wet grinding in a single semi-autogenous (SAG) mill and single ball mill, and followed by a gravity gold circuit and a conventional carbon-in-leach circuit. The prefeasibility study’s mine plan is estimated to provide sufficient ore (life-of-mine gold head grade of 0.71 gram of gold per tonne) to support an average annual production rate during years 1-5 of 378,300 ounces of gold per year, and an annual production rate of approximately 294,100 ounces of gold per year over an estimated 23-year mine life, producing a total of approximately 6.8 million ounces of gold.

Since well before WWII, several small prospects were known in the area that would become this prospect; these include the Griffin, Lillian Creek, Ruth Creek, and Old Smoky prospects. Beginning in the mid-1970s, a succession of companies have explored the area around Money Knob by mapping, and geochemical and geophysical surveys in the search for a large, bulk-mineable gold deposit (Brechtel and others, 2011). Homestake Mining Company drilled 6 holes in 1976; Occidental Petroleum drilled 6 holes in 1981; Amax Exploration drilled 3 holes in 1991; Placer Dome drilled 9 holes in 1995 and 1996; and Cambior Inc. explored in 2001 and 2002.

As of August, 2011, at a cutoff grade of 0.22 gram of gold per tonne, the Livengood deposit has a measured and indicated resource of 933 million tonnes with an average grade of 0.55 gram of gold per tonne (or 16.5 million ounces of gold). At the same cutoff, there is an additional inferred resource of 257 million tonnes with an average grade of 0.50 gram of gold per tonne. The estimation of a reserve was not possible at that time.