The McCarthy quadrangle contains numerous and diverse mineral deposits in various geologic settings. Copper is the dominant mineral commodity, both historically and in terms of potential future production. Gold and silver are the only other metals that have been produced. The metalliferous deposits are concentrated in a northwest-trending belt along the southern flank of the Wrangell Mountains, and, to a lesser extent, in a similar belt along the northeast flank of the range. Both belts have upper Paleozoic (Skolai Group) basements, abundant Mesozoic rocks, and some Tertiary intrusive rocks. They are marked by numerous faults, mainly northwest-striking. Mineral deposits are uncommon elsewhere in the quadrangle, especially in large tracks underlain by Wrangell Lava and in smaller areas underlain by the Kaskawulsh Group of Kindle (1953). Both the Wrangell Lava and the Kaskawulsh underlie rugged mountainous regions with extensive snow and ice cover, and could conceivably contain undetected concealed deposits. 

The metallic, nonmetallic, and energy resources of the quadrangle are described sequentially. Copper, gold, and silver, because of their importance, are described early in the section on metal commodities; descriptions of the other metals follows in alphabetic sequence. Locations of the deposits and relative supplementary data for individual deposits are given in the accompanying map and table.