Calico PROJECT
California
Located in mining-friendly San Bernardino County, California, Apollo’s Calico Project combines the Waterloo and Langtry silver properties under one common ownership for the first time.
OVERVIEW
The Calico Project (“Calico” or the “Project”), comprising the adjacent Waterloo, Langtry and Mule properties, is located in the historic Calico Silver Mining District in the Mojave Desert of San Bernardino County, California. Under Apollo, the Waterloo and Langtry properties have been combined for the first time. These represent a district-scale mineral system endowment with approximately 6,000 metres (19,680 feet) in mineralized strike length. The Calico Project hosts low-sulfidation epithermal-vein type and disseminated-style silver-barite mineralization, which is open to depth and along strike. Previous operators completed more than 42,000 metres (138,094 feet) of drilling across 438 holes on the Waterloo and Langtry properties.
Apollo recently announced an updated mineral resource estimate (“MRE”) for the Calico Project (the “2025 MRE”), which now contains 125 million ounces silver in 55 million tonnes (Mt) at an average grade of 71 grams per tonne (g/t) silver in Measured and Indicated category, and 0.51 Moz silver in 0.6 Mt at an average grade of 26 g/t silver in the Inferred category all at Waterloo. The Langtry mineral resource estimate has increased from 50 Moz to 57 Moz of Ag in 24 Mt at an average grade of 73 g/t Ag. At Waterloo, drilling data supporting the 2025 MRE includes information from historic drilling and 2022 drilling data for a total of 343 holes (28,407 m/93,199 ft), and at Langtry a total of 183 historic holes (23,465 m /76,986 ft) was used.
In addition to its robust silver resource, the Waterloo resource now contains 130,000 ounces of oxide gold contained in 17 Mt at an average grade of 0.25 g/t gold in the Inferred category.
The Calico Project 2025 MRE has been prepared by Derek Loveday, P. Geo., of Stantec Consulting Services Ltd. (“Stantec”), who is an independent “qualified person” as such term is defined in NI 43-101 (a “Qualified Person”), in co-operation with Mariea Kartick, P.Geo. (an independent Qualified Person for drilling data quality control and quality assurance) and Johnny Marke P.G. (an independent Qualified Person for resource estimation). The 2025 MRE was produced in conformance with the Canadian Institute of Mining Metallurgy and Petroleum (“CIM”) “Estimation of Mineral Resource and Mineral Reserves Best Practices” guidelines and are reported in accordance with NI 43-101. The 2025 MRE has an effective date of June 30, 2025. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that any mineral resource will be converted into a mineral reserve.
PROJECT LOCATION AND ACCESS
The Calico Project is well-placed relative to infrastructure and is located in the mining-friendly jurisdiction of San Bernardino County, California. The Project comprises the adjacent Waterloo, Langtry and Mule properties, which total 8,283 acres. The Project is 15 kilometres (9 miles) from the city of Barstow and has an extensive private gravel road network spanning the property. There is commercial electric power within 5 kilometres (3 miles) of the Project.
Other mines of note in the region include SV Minerals Searles Lake Boron project, MP Materials Mountain Pass rare earth element mine and Equinox Gold’s Castle Mountain gold mine. Equinox Gold has received acceptance of its project into the United States’ FAST-41 program, which is designed to streamline and derisk the permitting process. Rio Tinto’s Boron mine is near the border with San Bernardino County, in Kern County.
TENURE
The Calico District claims comprise the Waterloo and Langtry properties, combined consisting of
Private lands at both Waterloo and Langtry have received a Certificate of Land Use Compliance, vesting surface mining rights, which simplifies certain permitting processes. The unpatented claims on BLM-managed public lands are open for mineral entry, and no monuments, preserves or national parks encroach on these lands.
WATERLOO PROPERTY
The Waterloo property comprises 27 fee simple land parcels (1,352 acres) and 21 unpatented claims (19 lode mining, 2 mill site claims) (418 acres). These were acquired by Apollo through an Asset Purchase Agreement between Stronghold Silver USA Corp., a wholly-owned subsidiary of Apollo and Pan American Minerals Inc. (“Pan American”; a wholly-owned subsidiary of Pan American Silver Corp.), that closed July 13, 2021. Pan American retains a 2% Net Smelter Royalty on the property.
LANGTRY PROPERTY
The Langtry property comprises 20 patented claims (413 acres) and 38 unpatented lode mining claims (767 acres). The Project is under option between Stronghold Silver USA Corp., a wholly-owned subsidiary of Apollo, and the Bruce and Elizabeth Strachan Revocable Living Trust for the patented claims, and Athena Minerals Inc. for the unpatented claims.
MULE PROPERTY
The Mule property comprises 418 unpatented lode mining claims (5,473 acres) The Property was acquired by Stronghold Silver USA, from Lithium America Exploration LLC (“ Lithium Americas”), a wholly-owned subsidiary of Lithium Americas Corp. Lithium Americas retains a 2% net smelter return royalty on the Mule Property claims.
CALICO PROJECT MINERAL RESOURCE ESTIMATE
The Calico Project is comprised of two separate resources: the Waterloo Property and the Langtry Property.
The Waterloo resource contains 125 million ounces (Moz) silver in 55 million tonnes (Mt) at an average grade of 71 grams per tonne (g/t) silver in Measured and Indicated category, and 0.51 Moz silver in 0.60 Mt at an average grade of 26 g/t silver in the Inferred category. The Langtry MRE resource contains 57 Moz silver in 24 Mt at an average grade of 73 g/t silver.
In addition to its robust silver resource, the Waterloo resource now contains 130,000 ounces of oxide gold contained in 17 Mt at an average grade of 0.25 g/t gold in the Inferred category.
The Calico Project 2025 MRE was prepared by Derek Loveday, P. Geo., of Stantec Consulting Services Ltd. (“Stantec”), who is an independent “qualified person” as such term is defined in NI 43-101 (a “Qualified Person”), in co-operation with Mariea Kartick, P.Geo. (an independent Qualified Person for drilling data quality control and quality assurance) and Johnny Marke P.G. (independent Qualified Person for resource estimation). The 2025 MRE was produced in conformance with the Canadian Institute of Mining Metallurgy and Petroleum (“CIM”) “Estimation of Mineral Resource and Mineral Reserves Best Practices” guidelines and are reported in accordance with NI 43-101. The 2025 MRE has an effective date of June 30, 2025. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that any mineral resource will be converted into a mineral reserve.
- Ounces reported as troy ounces.
- Drilling information utilized for mineral resource estimation included exploration drilling records: 343 holes, 93,199 ft (28,407 m) at Waterloo and 183 holes, 76,986 ft (23,465 m) at Langtry.
- Base-case resource estimate reported in Table 1 using 47 g/t Ag equivalent (“AgEQ”) and 0.17 g/t Au cut-off grades for Waterloo and 43 g/t Ag for Langtry.
- CIM definitions are followed for classification of the mineral resource.
- For the Waterloo Property, a AgEQ cut-off grade was calculated using the following variables: surface mining operating costs (US$2.8/st), processing costs plus general and administrative cost (US$26.5/st), Ag price (US$28/oz), BaSO4 price (US$120/t), Zn price (US$1.22/lb), Au price (US$2,451/oz), and metal recoveries (Ag 65%, Au 80%, BaSO4 85%, Zn 80%). For the Waterloo Property gold-only resources the Au cut-off grade was calculated using above Au price, Au recovery and gold-only processing costs plus general and administrative cost (US$8.2/st).
- For the Langtry Property, a silver-only equivalent cut-off grade was calculated using above Ag price, Ag recovery and silver-only processing costs plus general and administrative cost (US$24/st).
- Resources reported in Table 1 are constrained to within a conceptual economic pit shell targeting mineralized blocks within the specified cutoff grade limits shown in the table. Specific gravity for the mineralized zone is fixed at 2.44 t/m3 (13.13 ft3/st). For the Waterloo Property only the following drillhole grades were capped prior to estimation: Ag 450 g/t, Au 2 g/t, Ba 31% and Zn 7%.
- Totals may not represent the sum of the parts due to rounding.
- 1,2The 2025 MRE has been prepared by Derek Loveday, P. Geo., of Stantec Consulting Services Ltd., an independent Qualified Person, in co-operation with Mariea Kartick, P.Geo. (independent Qualified Person for drilling data QA/QC) and Johnny Marke P.G. (independent Qualified Person for resource estimation). The 2025 MRE was produced in conformance with NI 43-101. Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that any mineral resource will be converted into a mineral reserve.
- No drilling was completed on the Waterloo Property and Langtry Property since the declaration of the 2023 MRE for Waterloo and 2022 MRE for Langtry. The 2025 MRE update accounts for changes in commodity prices, mining costs since 2022/2023, and barite testing of existing drill samples from the Waterloo Property.
For more information regarding the Calico MRE please see the following:
GEOLOGY
The Calico District is situated in the Calico Mountains of the Mojave Desert, in the west-central part of the Basin and Range tectonic province. The Calico Mountains consist of a 15 kilometre (9 mile) long northwest-southeast trending range dominantly composed of Tertiary (Miocene) volcanics, volcaniclastics, sedimentary rocks and dacitic intrusions.
The Calico Mountains form an uplifted block in a wedge-shaped zone between three major fault systems: the San Andreas Fault, the Death Valley Fault and the Garlock Fault.
Silver mineralization is associated with mid-Tertiary volcanic activity and northwest-trending fracture zones. Tertiary geologic units in the Calico area are the Pickhandle Formation (volcanic flows, breccias and volcaniclastics primarily of dacitic to andesitic composition) and Barstow Formation (sediments deposited in a shallow lake environment), overlain by the younger (Plio-Pleistocene) Yermo Formation.
Mineralization at Calico occurs as discrete NW and EW striking, high-grade silver-barite veins (primarily hosted in the Pickhandle formation) and broad disseminations and veinlet stockworks (primarily hosted in the Barstow sandstones). Both styles are believed to have formed from a common event, with the host rock controlling the style of mineralization. The timing of mineralization is ~15-20 Ma which aligns with a period of subduction and extension in the region.
Oxide gold mineralization underlies the silver mineralized stratigraphy and was drill defined over 1 km strike length in 2022. The gold mineralisation, which is mainly found at the contact between the Pickhandle and Barstow Formation, remains open in all directions. The continuation of the Calico Fault is present on the Mule property.
TECHNICAL REPORTS
HISTORY OF THE CALICO DISTRICT
Silver rich mineralization was discovered in the Calico mountains in 1881 with later extraction focused on high-grade oxidized deposits of vein-related silver. At its height of silver production between 1883 and 1896, Calico had over 50 mines and a population of 1,200 people. Historical estimates of total extracted silver up until 1896 are estimated to be between 15 and 20 Moz (Harthrong, 1983). Most mining of silver ceased in 1896 due a sharp decline in silver prices and an economic depression, with only limited production continuing until the 1930’s. One of the major silver producers in the district was the Waterloo silver mine, which is located on the Calico Project.
Barite became a mineral of interest in the region in the 1950’s as oil and gas exploration ramped up in the US. There was a concurrent reopening of silver mining, but production remained low. The Leviathon mine near the Langtry property was the largest barite producer on the west coast between 1957-1961. Numerous past-producing mines and historical workings are in the vicinity of the Waterloo and Langtry properties.
More modern exploration commenced on the Waterloo property in 1964, when the American Smelting and Refining Company (“ASARCO”) acquired an interest. ASARCO completed a significant amount of technical work including surface sampling, mapping, trenching, drilling and metallurgical testing. They completed an Environmental Impact Assessment report and feasibility in 1980, ultimately receiving a permit to mine. The decline of silver prices at the time resulted in a half of activities and put the project on care and maintenance. Pan American Minerals Inc. (a wholly-owned subsidiary of Pan American Silver Corp.) acquired an initial interest in the project in 1994, acquiring a 100% interest in 1996. Between 2008 and 2012, Pan American completed both reverse circulation and core drilling.
At Langtry, records show the property was acquired by an agent of Superior Oil Corp. (“Superior”) in 1966, with discovery of the disseminated silver mineralization occurring around 1967. Exploration by Superior from 1967 to 1984 consisted of geological mapping, geochemical sampling, surface trenching, drilling and metallurgical testing. Superior was subsequently purchased by Mobil Corporation and the Langtry property sat dormant due to depressed silver prices until the Strachan family acquired the private lands in 2004. Athena Minerals Corp. (“Athena”) acquired interest in the unpatented claims surrounding the private lands in 2010. A joint venture between Athena and the Strachan family saw a program of surface sampling, trenching and drilling completed by Athena in 2012. A total of 213 drillholes (26,200 metres/86,000 feet) is reported to have been completed on the Langtry Property by the previous operators. Of these, Apollo has audited data for 183 holes, 23,465 m (76,986 ft) which were used for the maiden Calico Project mineral resource estimate.