On August 2, 1900 an agreement was made with West Virginia Spruce Lumber Company for them to supply pulpwood to the West Virginia Pulp and Paper Company in Covington at a set price. The delivery of spruce to Covington however was delayed as the mountain railroad at Cass was completed before the Chesapeake and Ohio reached Cass. It was reported to the stockholders and recorded in the minutes of the directors meeting dated December 20, 1900, "that the Covington Mill was now thoroughly equipped and in good running order but there was a delay on the part of the C&O Railroad in completing the Greenbrier Junction, which was delaying wood supplies. The Covington mill started operation with approximately 300 employees and rated production of 15,000 tons of pulp and 7400 tons of paper per year.

In 1902, the pulp mill at Davis, West Virginia was rebuilt and it's capacity was doubled to 30 tons per day. Also the sulphite pulping process at Luke was replaced by the soda process.

In 1904, the Duncan Mill at Mechanicville, New York was added to the West Virginia Pulp and Paper Company. It was comprised of a sulphite pulp mill, a soda pulp mill and a six-machine paper mill. In 1906, the company acquired the Williamsburg Paper Manufacturing Company in Williamsburg, Pennsylvania. This mill consisted of a soda pulp mill and a two paper machine paper mill.

Paper machines 6 and 7 were added to the Luke mill in 1904. The mill consisted of seven paper machines at that time. A bleach plant was built at Luke in 1906 and operated by the Industrial Chemical Company. Sulfite pulp was used at Luke but was produced at the pulp mill in Davis, West Virginia.. A rag plant was added for speciality papers and a coating mill was added for producing coated papers. The first coated paper was shipped in 1907. In 1908, the Cass Timberlands totaled 50,000 acres.

In Covington in 1908, a lease was signed with the Robeson Process Company for a liquor disposal plant. This plant used the sulphite liquor left over after pulping to make "GLUTRIN". Glutrin was a product used as a binder for sand cores in foundries, as a disinfectant and as a priquetting agent for fine coat and iron pyrites. The Covington Plant was the largest in the world. Five hundred barrels of sulphite liquor was made into 500 barrels of Glutrin every day. This plant made a profitable product out of liquor that had previously been discharged straight into the Jackson River. This plant was installed in 1910 and ran until 1929.

On September 20th 1909, the assets of The West Virginia Pulp and Paper Company of West Virginia were conveyed to the West Virginia Pulp and Paper Company of Delaware. The total employees for the company were: Luke, 1,000, Mechanicville, 1,000; Tyrone, 700; Williamsburg, 500; Covington, 400; and Davis, 250.

In 1910, No. 3 and 4 Paper Machines were started up at Covington. They were installed as an expansion of the Sulphite mill.