The area of the Highland occurrence is underlain by rocks of the Pennsylvanian, and possibly Permian, Mount Roberts Formation which may be correlative with the Milford Group farther north. The Mount Roberts rocks are comprised of siliceous siltstone, argillite, silty chert, limestone or dolomite and minor sandstone and greenstone. The main western contact of the Trail pluton of the Middle to Late Jurassic Nelson Intrusions occurs within a kilometre to the east. A mass of granite related to the Nelson Intrusions occurs along the southern boundary of the Highland Crown Grant.

A large body of low-grade siliceous ore containing a large quantity of copper is reported to occur (Hodges, 1897).