Volcanic in origin, Indian Rock is the largest of a number of similar rhyolite rock formations in the vicinity, including the smaller rocks in the portion of the park on the east side of Indian Rock Ave. For example, only one block farther up the east side of Indian Rock Avenue is the  Mortar Rock Park, which has its own complex of granite outcroppings.
Indian Rock, formed by volcanic activity, is the largest of several similar rhyolite rock formations in the area, including smaller rocks found on the eastern side of Indian Rock Avenue.  Mortar Rock Park, located just a block further up the east side of Indian Rock Avenue, features its own collection of granite outcroppings.