The Pilot Ext prospect is located on the northeast side of Walker Ridge, approximately 75 kilometres west of Lillooet, near the west edge of Gun Lake.

Locally, the property is underlain by intrusives of the Coast Plutonic Complex, Bralorne diorite, ultramafics and Bridge River Group sediments.

Mineralization occurs as quartz-pyrite-chalcopyrite and/or bornite veinlets up to 3-5 centimetres thick within the granodiorite of the Coast Plutonic Complex, as well as narrow arsenopyrite veins.

The area was first explored in 1917 when the Ypres claim group was staked by Messrs. O. Fergusson and C. Walker. Gun Lake Gold Mines Ltd. acquired the property in 1931 and transferred it to Cariboo-Bridge River Gold Properties in 1933. The property was purchased by Pilot Gold Mines Ltd. in 1934, who developed the nearby Pilot Mine workings (MINFILE 092JNE027).

The Pilot Ext showing was first discovered by Cogema Canada Ltd. in 1991. At the time, Cogema Canada Ltd. was conducting an exploration program on the Pilot claim group consisting of mapping; prospecting; rock, soil and stream sampling and VLF-EM and magnetic geophysical surveys. Highlights of this program include rock sample 015R, which assayed 25.1 grams per tonne gold, 5.5 grams per tonne silver and 0.34 per cent copper (Assessment Report 22117).

In 1992, Cogema Canada Ltd. completed detailed mapping, prospecting, chip and grab rock sampling and a small drill program. Highlights include drillhole PLT-3, which intersected a 10.5 metre section grading 1 gram per tonne gold and 0.16 per cent copper, and grab sample BR1066R, which assayed 106 grams per tonne gold and 27.4 grams per tonne silver (Assessment Report 22759).

No work was completed by Cogema Canada Ltd. after 1992, and the claims lapsed.

In 2004, the claims were staked by Daryl Calder for Charles J. Grieg and J. Bernard Kreft, who renamed it the Gunner property. Charles J. Grieg then conducted a small prospecting program.