Sep 12, 2008. /Lesprom.com/. Faced with a flat housing market and declining demand for wood products, Plum Creek announced that it will reduce the number of rotating shifts at its Medium Density Fiberboard plant in Columbia Falls, Montana, from four to three. This will affect approximately 35 positions. However, employees will have the opportunity to apply for jobs at other Plum Creek facilities in the Flathead Valley. Currently 185 production employees work at MDF.