Which section of the "volcanoes"page of the ready. gov website cautions people to be aware of mudflows

gothic and dark natured

the symbol of the grandfather's heritage in this excerpt from "the medicine bag,” is the beaded bolo tie.

a bolo tie is a cord fastened around the neck with an ornamental clasp which is worn as a necktie. they have been used by native american tribes such as hopi, navajo, zuni, and puebloans since the mid-20th century.

therefore, the fact that the grandfather is wearing a bolo tie refers to his heritage as native american.