The Pet occurrence is located about 4 kilometres southeast of Mount Carter, approximately 32 kilometres north of the community of Atlin.

A minor amount of molybdenite flakes occur in quartz veins in alkalic granite of the Fourth of July Creek batholith (Middle Jurassic Three Sisters Plutonic Suite). Aplitic dikes are commonly associated with these veins.

In 1980, the Pet 1-4 claims were staked on behalf of Mattagami Lake Exploration Limited in response to a regional stream sampling program that revealed several copper-molybdenum anomalies in the drainage system of a large plateau east of Atlin Lake. Follow-up field work during 1981 consisted of detailed geochemical sampling and geological mapping which yielded a total of 400 samples.