While still working on the Railway Post Office route from McNeil, Arkansas, into north Louisiana, Couch was exposed to the development of the long-distance telephone. Believing he could earn money distributing telephone service, he formed a partnership with the postmaster of Bienville, Louisiana, Ben Cheen. In the spring of 1903 they completed 15 miles of telephone line construction from Bienville to Arcadia, Louisiana. After buying out Cheen's share of the business for $1,000, Couch and friend Dr. H. A. Longino formed the North Louisiana Telephone Company. By 1910 the company had constructed more than 1,500 miles of line, serving 50 exchanges in four states. In 1911, at age 34, Couch sold the company to Southwestern Bell Telephone Company, giving him a profit of more than $1 million. His business interests in Louisiana brought Couch into political alliance with Huey Pierce Long Jr., the flamboyant governor and United States senator.