The Khyber West occurrence is located approximately 10 kilometres south of the Iskut River in northwestern British Columbia; 95 kilometres northwest of Stewart. It is approximately 1 kilometre west of the Khyber Pass prospect (104B 138).

Regionally, the area is underlain by stratified rocks of the Upper Triassic Stuhini Group and Upper Triassic to Lower Jurassic Hazelton Group, which are intruded by Jurassic plutons and smaller bodies considered comagmatic with the Hazelton Group (Assessment Report 35943). Epiclastic and volcaniclastic rocks of the Stuhini group are unconformably overlain by siliciclastic, volcanic, and volcaniclastic rocks of the Hazelton Group. These strata are cut by diorite, quartz diorite, and monzodiorite plutons, plugs, and dikes of the Lehto suite (Paper 2015-1, pp. 41-58).

In the area of the Inel (MINFILE 104B 113) and Khyber Pass occurrences, the Sky-Khyber Deformation Zone is a planar deformation zone that strikes approximately 140 degrees, appears to have a shallow to 40 degrees southwest dip, and has a strike length of over 25 kilometres. The Sky-Khyber Deformation Zone has a protracted history and has strong relationship to the development of rock alteration and gold and copper mineralization (Assessment Report 35943).

Intrusive related rock alteration and mineralization are present at the Khyber West occurrence, and more broadly across the Inel-Khyber areas. Alteration is dominated by quartz-sericite-pyrite assemblages with localized minor potassic alteration. Quartz-sericite-pyrite pervasively replaces the matrix of the host rock and secondary potassium feldspar occurs as vein selvedges and as fine-grained matrix replacement that locally overprints quartz-sericite-pyrite alteration (Assessment Report 35943).

Historically the area has been explored as Khyber Pass, where Khyber West had been referred to as the South Zone. In 1990 Western Canadian Mining sampled a 9-metre continuous chip sample that assayed 4.6 grams per tonne gold and 0.66 percent copper (Assessment Report 35184). Refer to MINFILE 104B 138 for information on the early work history in the immediate area.

As part of exploration of the larger KSP property, work in 2014 by Colorado Resources identified a 500 by 200 metre gold and copper geochemical (rock and soil) anomaly at Khyber West. Rock sample 2635006, a random rock chip sample of quartz-pyrite altered rock, taken across 12 metres, assayed 3.105 grams per tonne gold, 17.2 grams per tonne silver, and 0.083 per cent copper (Assessment Report 35184).

Drillhole KSP14-001 was drilled in 2014 to test a zone of strong quartz-sericite-pyrite alteration and a gold and copper geochemical anomaly. The hole collared in strongly altered siltstone and intersected a weakly altered granodiorite at 17.63 metres. The hole was abandoned at 32.92 metres due to technical drilling difficulties and severe weather conditions. Assay results reported an average of 0.243 gram per tonne gold and 0.026 per cent copper over the length of the hole (Assessment Report 35184).

In 2017, Colorado Resources completed a total of 11,824 metres of diamond drilling in 24 holes at the KSP property. Including drill testing the Inel-Khyber (104B 138) and Tami (104B 116) zones. Drilling on the Khyber Pass zone (104B 138) included 3 diamond drill holes and on the Khyber West (104B 665), 2 drill holes.

Two drill holes (KBDDH17-096 and 097) were drilled in the West Khyber area approximately 1 kilometre to the west of the Khyber drill holes (KBDDH17-093 to 095). KBDDH17-096 was drilled to the north towards the BRDZ and KBDDH17-097 was drilled vertically from the same location. INDDH17-096 yielded 34 metres of 0.70 gram per tonne gold including 1 metre of 10.60 grams per tonne gold and KBDDH17-097 yielded anomalous gold and copper values throughout much of the drill hole and ended in 24 metres of 0.78 gram per tonne gold and 0.09 per cent copper (Colorado Resources Ltd., News Release, November 6, 2017). The intrusive phases, alteration patterns, and gold-copper geochemical signatures at West Khyber may suggest proximity to an intrusive related gold-copper system.

Colorado Resources Ltd. announced its name change to QuestEx Gold & Copper Ltd. on Sept 16, 2020.