The CZ (Fly 25) occurrence is located near a small swamp or pond, approximately 1.5 kilometres northeast of Lemon Lake and 10.5 kilometres northeast of the community of Horsefly.

Copper mineralization is associated with the Triassic-Jurassic(?) monzonitic to dioritic Lemon Lake stock, which occurs within volcanic rocks of the Nicola Group in the central Quesnel belt. The stock has intruded Upper Triassic basalt and overlying Lower Jurassic breccias containing felsic volcanic and plutonic clasts. These latter breccias are partly coeval with, and form an apron about, the felsic stock. Both the volcanic and the intrusive rocks have alkalic to subalkalic compositions with shoshonitic affinities.

The volcanic rocks adjacent to the stock and parts of the stock itself have undergone propylitic alteration, characterized by the development of calcite, chlorite and epidote. Zeolite alteration in places may also be of hydrothermal origin. Biotite alteration and secondary potassium feldspar is commonly associated with copper mineralization in syenodiorite and monzonite. Copper mineralization also occurs sparsely in the surrounding volcanics. Weakly anomalous gold values have been determined in propylitized volcanic rocks surrounding the stock. Mineralization consists of chalcopyrite, bornite, malachite, pyrrhotite, magnetite, pyrite and molybdenite.

In 1974, a percussion drill hole (74L-4) on the Fly 25 claim intersected a variably k-feldspar-altered biotite monzonite yielding 0.18 per cent copper over 39 metres, including 0.252 per cent copper and 0.34 gram per tonne gold over 21 metres and 0.700 per cent copper and 0.69 gram per tonne over 3 metres (Property File - Mt. Calvery Resources Ltd. [1981-01-01]: Data Compilation - Lemon Lake Cu/Au Prospect).

Since the 1960s, the Lemon Lake area has been explored for gold and silver potential. Historical work includes geophysical surveys, soil and rock sampling, prospecting, geological mapping, trenching and reverse circulation, percussion and diamond drilling.