Unlike many rural outposts there is usually some sort of a nucleus of buildings. There is always an exception to the rule, and Merrillville is one of them. In the early 1870s,the residents of Willow Creek Valley desired mail service. It was Willow Creek blacksmith, Orman Folsom who led the movement. On April 1, 1875 the Merrillville Post Office was established at the Folsom Ranch, (Willow Creek Wildlife Unit), with Orman Folsom as postmaster. Folsom named the post office after Captain Charles A. Merrill who had recently arrived on the scene to tap Eagle Lake for reclamation. Folsom and his successors never had any intent to establish a town. The post office location changed over the years and when it was discontinued, on November 30, 1928, it was located at the Stone Ranch, Eagle Lake.