The Kleanza copper prospect (Croesus claims 1-130) covers Kleanza Mountain, about 12 kilometers north east of Terrace. Kleanza Mines Limited staked the initial Croesus group in 1965-66. During 1967-68 exploration work continued on the Croesus, Excelsior (130I 081), Gem (103I 136) and other properties.

Andesite of the Jurassic Hazelton Group is intruded by grano- diorite of the Cretaceous to Tertiary Coast Plutonic Complex. A quartz vein sparsely mineralized with pyrite strikes 150 degrees and dips 35 degrees east within the volcanics. The vein averages 76 centimetres in width and is exposed intermittently for 400 metres. A 100 centimetre wide sample from the southeast part of the vein assayed 1.4 grams per tonne gold and trace silver (Geological Survey of Canada Memoir 205).