The June issue of Railpace had an article about the R&N Humboldt operation. It said there are 70 companies in the park, 10 currently served, 9 more w/ sidings but not being used, and 9 more empty sites for development that can get rail. Scanning the article, of the 10, I see International Paper, Pro Con warehouse, Karchner Logistics, Cargill, & Quad Graphics. Can't help on the other 5. In 2014, 4600 cars were handled, before the takeover. JS
EDIT: I missed one. Add "Vita Line"