The Armstrong Zone geochemical anomaly is located on the western slope of Manuel Creek, approximately 7 kilometres northeast of Keremeos.

The area is underlain by Eocene volcanics of the Penticton Group.

Locally, a northeast trending fault zone hosts altered volcanics. The zone consists of an argillically altered silicified core with peripheral propylitic alteration of the feldspar-biotite porphyritic Kitley Lake volcanics.

The area was originally explored by Pacific Petroleum (Petro Canada) for uranium from 1976 to 1978. Between 1989 and 1991, the area was explored as a part of the EPI 1-13 claims by G.F. Crooker. This included programs of geological mapping, prospecting, magnetic, VLF electromagnetic and induced polarization surveys. In 1989, sampling of altered Kitley Lake member volcanics returned up to 4 parts per billion gold, 1.3 parts per million silver and 16 parts per million copper (Property File: Lee, L. (1989-01-08)). In 1994, the area was claimed and explored as the EP claims.