In 1970, Henshaw became president of Homestake Mining Company. He led the company as president until 1977, when he became chairman of the board.[2] He was on the frontline of mine exploration and development. During his tenure the company became an established provider of uranium and expanded to include lead and zinc in Missouri as well as silver in Colorado. His excellent leadership led Homestake to place among the top financial performers among U. S. companies throughout the 1970s.[1][4]
In 1981, Henshaw was awarded the Charles F. Rand Memorial Gold Medal by the American Institute of Mining, Metallurgical, and Petroleum Engineers for "his unique combination of skills in innovating mining exploration, development, technology, and financial management, while serving fully his professional and civic responsibilities."[5]