Katharine was born in Little Boar's Head, New Hampshire in 1902 to William Plumer Fowler and Susan Farnham Smith.
As a child, for most of the year she and her family would live in Boston, but during the summer they would travel to their coastal home in Little Boar's Head.
From the age of seven up, until she left for college, Katharine would spend every August in Randolph, New Hampshire with a widow, where she developed an appreciation for the mountainous region.
[4] In 1938, she married Marland Pratt Billings, whom she met at Harvard while he was junior faculty, pursuing an attempt to establish his career as a professor.
[2] Her "publication record ... includes fundamental geological descriptions of large areas in Wyoming, Sierra Leone, and New Hampshire.
[4] When Fowler-Billings began her career, the field of geology predominantly consisted of men, and the sexism she faced often prevented her from conducting her research.
They mapped out Mount Washington which yielded a greater understanding of the complex structural geology of the White Mountains.
[2] By the end of the summer she had produced a geological map that identified all of what we now refer to as Laramie anorthosite complex (LAC).