An act of Congress approved in April 1878 gave the Utah & Northern Railroad Co. permission to build a narrow gauge line through Marsh Valley. It reached Oneida by July of 1878, where the first station was built. The town attained a population of about 2,000 as it was the forwarding point for the Soda Springs area until the Oregon Short Line came to McCammon in 1882. The first post office in this valley was established there, with Alma Hobson as postmaster. Oneida later changed to Arimo in honor of an Indian chief.