Success after 1889 was largely due to the identification of oil and gas deposits through the anticlinal theory, developed by geologist Israel C. White of West Virginia University. His theory was first tested in 1889 in Mannington and led to the 1900 discovery of the Copely well, which started the Lewis County oil boom. This shifted the oil industry from western West Virginia to the north-central area, benefiting companies like South Penn Oil (now Pennzoil) and Hope Natural Gas (now Hope Gas), both controlled by John D. Rockefeller’s Standard Oil.