The MANDUSA occurrence is located about 5.2 kilometres east-southeast of the AL (Thesis II/III) past producer (094E 091) approximately 293 kilometres north of Smithers, in the Toodoggone Gold Camp.

The Mandusa showing is underlain by andesitic volcanics of the Metsantin member of the Lower Jurassic Toodoggone Formation (Hazelton Group). In 1994, Alpine Explorations Ltd. reported rock samples with 0.8 and 1.2 grams per tonne gold (Figure 8, Assessment Report 23847). The samples are plotted on a map at the location of a north-northwest trending fault structure. In 2006, Paget Resources Ltd. reported gossanous silicified rocks with fine-grained pyrite; grab samples failed to confirm any gold mineralization.

In 1994, the GO claims were abandoned and the Mandusa group of three claims, covering 30 units, was staked by L. Hewitt to cover the ground of the original Lexim group. In 1994, Alpine Explorations Ltd. conducted a program of prospecting and soil sampling and reconnaissance geologic mapping in order to locate and confirm the anomalous results of the 1985 discovery of precious metal-bearing float. During this year, 83 rock and 162 soil samples were collected for analysis.

From 2006-08, Paget Resources Ltd. held the Mandusa showing area as part of its large Met property and visited the Surprise showing (094E 192), which they called the Cirque zone. In 2006, Paget reported gossanous silicified rocks with fine-grained pyrite at the Mandusa location, but grab samples failed to confirm any gold mineralization.

From 2020 through 2023, Thesis Gold Inc. completed programs of prospecting, mapping, geochemical (rock and soil) sampling, ground and airborne geophysical surveys, re-logging/re-sampling of historical drill core, and extensive digitization and compilation of existing exploration data on their Ranch property. From 2021 to 2023, 368 diamond drill holes, totaling 68,481.6 metres were completed on the Ranch property, with the majority of the drilling targeting the major prospects of Bonanza, Ridge, Bingo, Thesis II, Thesis III, BV, JK and Eric. Metallurgical testing and environmental monitoring/baseline and geotechnical studies and infrastructure upgrading were also initiated during this period, along with First Nations consultations. Drilling at the major prospects on the Ranch property expanded the known mineralized zones along strike and at depth.

In 2022, rock sampling of several occurrences on the Ranch property included the Mandusa showing. The most notable samples from Mandusa were grab samples B066260, which returned 0.71 grams per tonne gold and 13.45 grams per tonne silver and B066259 returning values of 0.6 grams per tonne gold and 22.3 grams per tonne silver (Assessment Report 41940).

In August 2023, Benchmark Metals Inc. merged with Thesis Gold Inc., joining the Lawyer Project, located in similar Toodoggone Formation rocks to the southeast, with Thesis Gold's Ranch Project.

A NI 43-101 & 43-101F1 Technical Report and Updated Mineral Reserve Estimate of the Lawyer-Ranch Gold-Silver Project was prepared for Thesis Gold Inc. by P & E Mining Consultants Inc. in May 2024 and an updated Preliminary Economic Assessment (PEA) was completed for the Lawyers-Ranch Project by JDS Energy & Mining Inc. effective August 30, 2024.

See Bonanza (094E 079) for further geological and work history details of the Ranch (Al) property, which contains the Mandusa showing (2025) along with a number of other prospects.