The Catspaw 146 occurrence is located between Frank Mackie and Berendon Glaciers. The area is underlain by rock of the Lower Jurassic Unuk River Formation, Hazelton Group. These consist mainly of siltstones and ash tuff with lesser dust and lapilli tuff and interbedded augite porphyry. Feldspar porphyry flows also occur (Open File 1987-22).

A 0.76 metre wide zone of sheared, brecciated, pyritized volcanic is reported. A grab sample contained 1.15 grams per tonne gold (Assessment Report 17027).

Work on the Catspaw claim in 1986 by Teuton Resources resulted in the discovery of the Catspaw showing (104B 211) and was followed up in 1987 by Wedgewood Resources with the discovery of the Catspaw 146 (104B 343) and Catspaw South (104B 288) showings. Work in 1990 and 1991 by Big I Development on the Portland/Haida claim (104B 082) coincided with work on the Catspaw claim, notably drilling on the Catspaw South showing. A large airborne geophysical program was conducted over the 4-J and Catspaw claims in 2006 at which time significant geophysical anomalies were reported to have been detected on the Catspaw claim.

Refer to Catspaw (104B 211) for details of work on the Catspaw claim and to 4-J (104B 128) for broader details on the 4J and Catspaw claims under the 4-J property umbrella.