Rick Rule is a veteran natural-resource investor who began in 1974, built Global Resource Investments (sold to Sprott in 2011), and led Sprott U.S. Holdings until retiring in 2021 to found Rule Investment Media. His free Substack covers contrarian speculation in mining, energy and critical minerals — gold, silver, copper, nickel, royalty and streaming companies — framed by geopolitical risk.
This piece is about mining investor Rick Rule being optimistic about MACK, a junior explorer that spent $37 million to consolidate land in Nevada's historic Comstock district. MACK's strategy is not to reopen old mines but to find shallow, 1 g/t oxide gold—considered 'very rich' for modern heap-leach operations. The company has $38 million in cash, plans most drilling by end-2026, and could release a first resource estimate as early as first-half 2027. The article also cites SSR Mining's $464 million acquisition of Roxmore as evidence that low-grade gold can be economic.
One-sentence summary of the author's market judgment for this period: Rick Rule holds an optimistic stance on MACK's Comstock district consolidation and exploration prospects, believing its consolidation strategy and geological model have the potential to become the next major discovery.
MACK spent approximately $37 million to consolidate the mineral rights of the Comstock district — a critical first step to unlocking the area's potential and a prerequisite for all subsequent exploration work.
The report argues that MACK's primary challenge is not geological but commercial. The mineral rights in the Comstock district were highly fragmented, with claims divided into small parcels overlapping potential mineralized structures. The author's original words: "The big challenge was fragmentation. Drilling was not followed up on a vein structure that you can see and walk." This fragmentation explains why some mineralized zones, despite encouraging historical drill results, were never systematically traced along strike or down dip.
MACK completed over a dozen acquisitions, agreements, and claim registration transactions, including a landmark deal with Comstock Mining for approximately $20 million, followed by agreements in September to acquire assets from Consolidated Virginia Mining and Marshall Earth Resources. The total cost of district consolidation was about $37 million — a significant investment for a junior exploration company, but one that created a sizeable land package. The consolidated claims cover three major mineralized structures: the 6 km-long Comstock Vein, the 4.5 km-long Occidental-Brunswick Vein, and the 6 km-long Silver City Vein. Green stated: "Through that deal, we now control all the mines that were the sources of historical production."
The acquisitions also brought historical exploration data, existing mining infrastructure, and the permitted American Flats processing facility (in care and maintenance since 2016). MACK has also actively repurchased existing royalties, including acquiring a 1.5% net smelter return royalty for $1 million prior to listing. Further consolidation remains possible.
This consolidation effort carries significant strategic value. MACK can now assess the continuity of mineralized structures over considerable strike lengths and plan potential mining and processing infrastructure on a district-wide scale, rather than exploring on isolated claim blocks.
Crucially, MACK has raised sufficient capital to advance its work. After completing a $60.2 million initial public offering (at $1.40 per share), MACK holds approximately $38 million in cash, with 87.7 million shares outstanding and a market capitalization of $170 million. About 30% of shares are held by institutions, such as Franklin Templeton with a 6.27% stake, while management and insiders hold 14%. Green deliberately raised more capital than immediately needed for drilling to address potential additional acquisition opportunities during the consolidation process. The company has exploration funding for at least several years, but the current focus is on proof of concept and understanding the geology. Green said: "We have a lot of money in the bank, and the temptation is always to put many rigs on the ground, but we want to drill at a measured pace so we don't get ahead of the geology."
The scale of the potential target has attracted many well-known figures in the exploration industry to join the MACK team, including bringing former Corvus Gold CEO Jeff Pontius out of retirement to serve as Chairman, and renowned Great Basin geologist Moira Smith as a technical advisor. Pontius sold Corvus to AngloGold Ashanti (NYSE:AU) for $370 million in 2022, when he was consolidating claims around his Silicon discovery in the Walker Lane belt. Both have visited the site multiple times this year. Agentis Capital's Michael Gray and Discovery Group's John Robbins have also joined the team, strengthening its capabilities.
MACK's exploration model identifies two distinct mineralization types — shallow, low-grade oxide gold and deeper, high-grade structurally controlled gold-silver — with the Occidental-Brunswick structure believed to have the geological characteristics to host both.
Comstock is a classic low-sulfidation epithermal gold-silver system, associated with Miocene volcanism and crustal extension in western Nevada. Approximately 15 million years ago, the region was stretched by extensional tectonics, creating faults and fractures that allowed hydrothermal fluids to rise through volcanic rocks. As fluids moved upward, changes in temperature, pressure, and chemical conditions caused gold and silver to precipitate in veins and related structures. The richest mineralization occurred where structural conditions created favorable pathways for fluid movement, particularly at fault intersections and dilation zones. These local enrichments produced the extremely high-grade ore shoots for which Comstock is famous. The system was subsequently disrupted by faulting, mass movement, and erosion, complicating the geology but potentially preserving mineralization at different structural levels.
MACK's exploration model identifies two distinct mineralization types. The first is widespread, relatively shallow oxide gold mineralization at around 1 g/t, suitable for evaluation as an open-pit heap leach resource. The second is deeper, structurally controlled high-grade gold-silver mineralization, where extremely high-grade ore shoots may occur within broader, lower-grade mineralized zones. Green believes the Occidental-Brunswick structure has the geological characteristics to host both. Importantly, the Occidental structure is not a speculative geological interpretation — it is exposed at surface, traceable along strike, and intersected by the historical Sutro Tunnel, where miners reportedly encountered a vein approximately 112 feet wide. At surface, near historical workings, banded quartz is visible — a classic textural and structural indicator of low-sulfidation hydrothermal veins, formed near the boiling zone of the subsurface hydrothermal system. The question is whether this structure contains mineralization with sufficient grade, thickness, and continuity to support an economically viable resource.
MACK’s goal is not to reopen the historic Comstock mine, but to establish a shallow oxide gold resource along the Occidental-Brunswick vein trend that supports modern open-pit heap leach mining. The report clearly states that while the company believes significant economic mineralization remains in the historic mines, the old workings are a labyrinth of complexity with slow exploration progress, making this a future task. The current priority is to define a shallow, heap-leachable oxide gold resource.
Addressing potential market misinterpretation of the 1g/t grade, management emphasizes that for modern open-pit heap leach operations in Nevada, 1g/t oxide gold is “very rich.” The author quotes CEO Darwin Green’s direct explanation for this seemingly contradictory phenomenon.
> “We have the history of one of the world’s greatest districts and we are hitting 1g/t. The market may misunderstand this, but 1g/t in gold oxide is very rich, and more than three times the grade of many economic mines in Nevada.”
The author then supports this view with the case of SSR Mining (NASDAQ/TSX:SSRM) acquiring Roxmore Resources (TSX:RM) :
Beneath the low-grade oxide ore, MACK is drilling the Sutro Tunnel to target high-grade gold-silver mineralization similar to the historic Comstock bonanza, representing a larger but more speculative opportunity. The Occidental-Brunswick vein trend runs parallel to the Comstock vein but is vastly underexplored.
MACK’s exploration story is not solely reliant on new discoveries; the company also controls the Lucerne and Dayton deposits, where historical drilling has delineated approximately 1 million ounces of gold. These deposits lie on the Silver City vein and represent a second major path to building a multi-million-ounce resource, independent of the success of the Sutro exploration.
| Deposit | Historical Resource Estimate | Key Historical Intersection | Next Steps |
|---|---|---|---|
| Dayton | Approximately 400,000 oz Au | 41m @ 7.5g/t Au (not adequately followed up) | Confirmation and infill drilling in 2027 |
| Lucerne | Not specified, but combined total ~1Moz | 20m @ 4g/t Au (drilling stopped thereafter) | Confirmation and infill drilling in 2027 |
| Ticker | Direction | Author's One-Sentence View | Key Data |
|---|---|---|---|
| MACK | Hold & Watch | Consolidation strategy is successful with promising exploration prospects, but mineralization continuity needs verification | Consolidation cost $37M; Cash $38M; Market cap $170M |
| SSR Mining (SSRM) | Not specified | Serves as a benchmark case, proving the economic viability of low-grade heap leach operations | Acquired Roxmore for $464M; Marigold mine average grade 0.44g/t |
| AngloGold Ashanti (AU) | Not specified | As the acquirer of Corvus Gold, indirectly linked to the MACK team's background | Acquired Corvus for $370M in 2022 |
| Kinross Gold (K) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |
| Coeur Mining (CDE) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |
| McEwen Mining (MUX) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |
| Integra Resources (ITRG) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |
| Equinox Gold (EQX) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |
| I-80 Gold (IAU) | Not specified | Listed as one of the potential acquirers in Nevada | N/A |