Wood, Morrell & Co. was the "company store" for the steelworks in Johnstown, Pa. The building basically survived the great flood, which Daniel Morrell had had intimations of happening. If you've never read David McCullough's "The Johnstown Flood," it's entertaining and blessedly short, and also goes into great detail about a department store owner named Quinn.
After the flood, the store was gradually separated from its company-store relationship and established as a publicly held company in 1903. But earlier, its name had been changed to Penn Traffic Co. for reasons that, as near as I can tell, have never been explained. I once spent time in the Johnstown library going through newspapers for the weeks before and after the name change, hoping that an ad or a news story would explain the name "Penn Traffic." None did. One day it was Wood, Morrell & Co.; the next, it was Penn Traffic, and that was that. It may have been the oddest name of any traditional U.S. department store, although Zion's Cooperative Mercantile Institution in Salt Lake City and the City of Paris Dry Goods Co. in San Francisco would give it a run for its money.
Penn Traffic never moved from its company-store location, though, on Washington Street a few blocks from Johnstown's Main Street. In this it also was singular; Kline's, Thomas' and Nathan's were on Main, Glosser's a short distance away. The isolation of the store is clear from the photo above. Not many cities had outlier department stores, ones that clearly were downtown but just as clearly were not and had never been on a main shopping street; Alms & Doepke in Cincinnati comes most prominently to mind, and Jordan Marsh's main Miami store. (Another category was big department stores that were based in neighborhoods, such as Schuster's in Milwaukee and Sattler's in Buffalo.)
Johnstown recovered from the flood but never really went anywhere after that; Penn Traffic had the same sort of career until it went into the grocery business, where it had great success. It eventually sold its department stores to Hess's, but kept its headquarters in the old downtown store until moving to Syracuse. A 1994 biography of the company is here.
Penn Traffic early went into branches outside the city, its earliest ones being in DuBois and Indiana, Pa. If memory serves, the Bon-Ton store in State College was opened as a Penn Traffic.