Mark L. Requa (December 25, 1866 – March 6, 1937) was an American mining engineer and petroleum conservationist.

[2][3] Isaac Requa was a one time president of Oakland Bank of Savings and made a fortune in silver and gold mining in Virginia City.

[4][5][6] He was also an engineer with Comstock Mining and served as president of the Central Pacific Railroad.

He helped to coordinate the production and marketing policies to enable the oil industry to support the military needs of the United States during the war.

In 1921, at the World Engineering Congress in Tokyo, Requa warned nations about wasting petroleum.

[1][12] Together, they had two daughters and one son: Mrs. John Henry Russell, Mrs. William David Coy Filmer and Lawrence Kendall Requa.

He died on March 6, 1937, at St. Vincent's Hospital in Santa Barbara following complications from an abdominal operation three weeks earlier.