The former Mission Mill Museum, now known as the Willamette Heritage Center, is said to be haunted by spirits of its past, including apparitions seen at the historic Thomas Kay Woolen Mill. Several structures on the 5-acre property are the subject of ghost stories, which have been collected as part of the center's "Spooky Stories" tours. The Thomas Kay Woolen Mill, a historic structure built in 1889, is one of the center's most famous haunted sites. Ghost hunters and visitors have reported seeing at least two apparitions within the woolen mill. The mill's industrial setting, with its dangerous machinery, may have contributed to a tragic history and lingering spirits. The Willamette Heritage Center has even featured a fictional horror story set at the mill about a ghostly visitor seeking justice.