The Mary (Jumbo) occurrence is located on the south side of Enterprise Creek, immediately west of Timber Creek and approximately 13.5 kilometres northeast of Slocan.

The area is underlain by granodioritic intrusive rocks of the Middle Jurassic Nelson Batholith.

Locally, a potassium feldspar porphyritic granite hosts at least three sub-parallel, oxidized and clay-altered shear or fault zones. The fracture zones, up to 1.5 metres wide, host quartz veins or pods mineralized with galena, sphalerite, pyrite and possible electrum. Siderite, carbonate, chlorite and possible sericite are also reported. The zones strike north 10 degrees east and dip 55 degrees west. Surface stripping and trenching have exposed the zones along strike for approximately 300 metres.

The Jumbo property consists of galena, sphalerite, chalcopyrite, and gold in the form of electrum mineralization in quartz/carbonate epithermal veins formed along fracturing within the Nelson intrusive rocks. Mineralization is predominately dominated in small, highly concentrated “pods.”

The Jumbo property has three distinct but similar mineralization zones; JBZ 1, JBZ 2, JBZ 3. The main mineralized zone, JBZ 1 zone, consists of a 1 to 2 metre wide pyritized alteration zone within a 10 to 15 metre wide sericite to propylitic alteration zone. This structure follows the long regional fault of Timber Creek with a total length of 500 metres. The gold mineralization in this zone occurs in a gangue of siderite alongside massive galena and sphalerite. Specifically, gold grade in the gossan zone in the adit area was observed from 27.84 to 31.40 grams per tonne, and silver grades ranging from 61.36 to 92.21 grams per tonne (Price, B. (2007-08-15): NI 43-101 Compliant Technical Report – Jumbo Silver Property). The second zone, JBZ 2, is an alteration zone above and west of JBZ 1 zone. Although unique because of subparallel north to northeast striking vertical shears, no significant mineralization is found. The third zone, JBZ 3, is located south and east of the JBZ 1 zone. It is unique because septa and narrow veins are found in pyritized and sericitized granodiorite associated alongside northeast striking fractures (Price, B. (2007-08-15): NI 43-101 Compliant Technical Report – Jumbo Silver Property). Chip sampling across 1 metre of the alteration and fracture zone graded silver at 117.92 grams per tonne (Price, B. (2007-08-15): NI 43-101 Compliant Technical Report – Jumbo Silver Property).

In 1967, diamond drilling is reported to have yielded up to 0.30 per cent lead, 4.70 per cent zinc, 6.8 grams per tonne gold and 271.9 grams per tonne silver over 75 centimetres in hole no.4 (Property File - R.W. Phendler [1970-03-11]: Report on the Mary Group of claims of Rockland Mining Ltd.).

In 1969, a chip sample (no. 29229) from the south end of a trench located approximately 100 metres south of the adit assayed 27.40 per cent lead, 20.5 grams per tonne gold and 807.1 grams per tonne silver over 0.6 metre (Property File - R.W. Phendler [1970-03-11]: Report on the Mary Group of claims of Rockland Mining Ltd.).

In 1974, underground sampling (no.13546) yielded up to 38.4 grams per tonne gold with 201.5 grams per tonne silver over 30 centimetres and 8.6 grams per tonne gold with 92.7 grams per tonne silver across 1.8 metres (Property File - J. Paxton [1981-11-05]: Assay and maps of Jumbo Claim on Enterprise Creek).

In 1983, sampling yielded up to 8.2 grams per tonne gold with 26.0 grams per tonne silver over 2 metres (sample J69) from the third adit and 2.7 grams per tonne gold with 76.0 grams per tonne silver over 1.5 metres (sample J72) from the second adit, whereas sample (J64) from a shear exposed in a trench assayed 4.15 grams per tonne gold with 32.0 grams per tonne silver over 1 metre (Property File - T.R. Stokes [1983-10-01]: Geology Map - Jumbo Claim - Map 1).

In 1987, a dump sample assayed 190 grams per tonne silver, 10 grams per tonne gold, 3.4 per cent lead and 0.48 per cent zinc (Open File 1988-11).

Production between 1973 and 1983 totalled 53 tonnes yielding 22 930 grams silver, 531 grams gold, 2665 kilograms lead and 1891 kilograms zinc.

The area has been explored by at least three adits and a number of opencuts. The occurrence was discovered in 1962 and, during 1965 through 1967, Timberline Mines drove at least one adit for a total of 18 metres, completed 90 metres of surface stripping and drilled six holes, totalling 152.4 metres. In 1969, a program of trenching was performed. In 1970, Rockland Mining examined the Mary property. In 1980 and 1981, Hoko Exploration, in conjunction with Alto Exploration, examined the property and drove a crosscut for 66 metres. In 1984, Golden Porphyrite completed a program of geological mapping and geochemical sampling. In 1989, Siscoe Callahan Mining acquired the property.