Kathryn Elizabeth Derr, 94, passed away peacefully with her sons by her side on Tuesday, December 5, 2017. She was born in Lancaster, Pennsylvania, on January 18, 1923 to the late Leonard J. and Barbara H. (Johnstin) Mattern. She was preceded in death by her husband Donald E. Derr, and infant son Donald Jr., and also by two brothers (Leonard Jr. and Eugene Mattern) and five sisters (Mildred Weibley, Frances Turner, Ruth Koenig, Barbara Pontz, and Ellen Hess.) Known as "Kassie" by friends and co-workers, she was employed at the Carpet House, the former Goldsmith Furniture Store, and later worked at Delta Dental until her retirement. She was the mother of two surviving sons, Michael E. Derr and partner Debra A. Mirenzi, and Thomas E. Derr and wife Sara. She is also survived by her sister Clara Davidson of Lancaster, Pennsylvania, and by numerous nieces and nephews. Kathryn was proud grandmother to Jeffrey, Wesley and Salena and great-grandmother to Tava, Greyden, and Aurelia. In keeping with Kathryn's wishes, there will not be a memorial service; burial will be private and at the convenience of her family. Memorial contributions can be made to the Bethesda Mission, P.O. Box 3041, Harrisburg, Pennsylvania 17105.